Solar energy storage system for building roof and energy storage method thereof

Abstract

This invention relates to the field of energy storage management technology, specifically disclosing a solar energy storage system for building rooftops and its energy storage method. The method includes the following steps: determining whether to generate a pulse trigger command based on real-time current values ​​and the state of charge (SBC) of the building rooftop energy storage battery; responding to the pulse trigger command, controlling the discharge circuit of the building rooftop energy storage battery to disconnect, and controlling the pulse generation circuit to apply a positive voltage pulse; after the positive voltage pulse ends, reconnecting the discharge circuit of the building rooftop energy storage battery; recording the real-time current value, the SBC of the building rooftop energy storage battery, and the amplitude and width of the positive voltage pulse each time a positive voltage pulse is applied; and updating the criteria for determining whether to generate a pulse trigger command based on the recorded data. This invention can improve the stability and lifespan of building rooftop solar energy storage systems under low-power operating conditions at night.

Description

Technical Field

[0001] This invention relates to the field of energy storage management technology, specifically to a solar energy storage system for building rooftops and its energy storage method. Background Technology

[0002] With the widespread adoption of building-integrated photovoltaics (BIPV) systems, the application of solar power generation combined with energy storage batteries has become a common form of rooftop energy utilization. In existing technologies, rooftop solar systems typically charge the energy storage batteries during the day and then provide continuous power to low-power loads within the building at night. These energy storage batteries often employ an electrochemical structure based on lithium-ion migration, and their long-term performance is significantly affected by the discharge mode.

[0003] During nighttime operation, the discharge current of energy storage batteries is typically at a low level, differing from the standard operating current designed for the battery. During this low-current discharge, the way lithium ions in the electrolyte participate in electrochemical reactions changes, making it difficult for their reduction and decomposition process on the electrode surface to proceed fully, easily generating decomposition products, primarily organic lithium salts. These decomposition products continuously accumulate on the electrode surface, forming a relatively loosely structured, high-impedance interface layer. This interface layer affects the uniform migration of lithium ions, leading to ion retention in localized areas.

[0004] In a state of ion retention, the retained highly active lithium continues to undergo side reactions with the electrolyte, further thickening the interface layer and causing gradual consumption of the electrolyte. As this process continues, the amount of active lithium available for energy storage within the battery decreases. After multiple charge-discharge cycles, the actual output capacity of the energy storage system gradually declines, leading to premature capacity decay and impacting the long-term lifespan of the building rooftop solar energy storage system. Summary of the Invention

[0005] The purpose of this invention is to provide a solar energy storage system for building rooftops and its energy storage method, thereby solving the aforementioned technical problems.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for solar energy storage on building rooftops includes the following steps: During the discharge phase of the building rooftop energy storage battery, the real-time current value of the discharge circuit is continuously monitored, and a pulse trigger command is generated based on the real-time current value and the state of charge of the building rooftop energy storage battery. In response to a pulse trigger command, the discharge circuit of the building rooftop energy storage battery is disconnected, and the pulse generation circuit is controlled to apply a positive voltage pulse between the positive and negative terminals of the building rooftop energy storage battery within a preset pulse width. After the positive voltage pulse ends, reconnect the discharge circuit of the building rooftop energy storage battery; Record the real-time current value, the state of charge of the building rooftop energy storage battery, and the amplitude and width data of the positive voltage pulse each time a positive voltage pulse is applied; The standard for determining whether to generate a pulse trigger command is based on the updated recorded data.

[0007] As a further aspect of the present invention: determining whether a pulse trigger command has been generated includes: Within a preset time window, real-time current values ​​are acquired at fixed sampling intervals, and the number of times the real-time current value is lower than the low current threshold within the time window is counted. When the number of attempts reaches the threshold and the state of charge of the building's rooftop energy storage battery is higher than the state of charge threshold at the end of the time window, a pulse trigger command is generated.

[0008] As a further aspect of the present invention: the updated criteria for determining whether a pulse trigger command has been generated include: The average of the recorded real-time current values ​​is calculated and used as the updated low current threshold. Obtain the maximum value A1 and minimum value A2 from the recorded states of charge, and obtain the new state of charge threshold Y1=Y+(A1+A2) / 2, where Y represents the current state of charge threshold.

[0009] As a further aspect of the present invention: applying a positive voltage pulse includes: After the last positive voltage pulse is applied, the terminal voltage of the building rooftop energy storage battery is acquired at a preset sampling interval, the difference between two adjacent terminal voltages is calculated, and the difference is sorted in order of time axis. Group the differences, where all differences in a single group are greater than 0 or all differences are less than 0, and the difference j in a group is adjacent to at least one difference in the same group in the sorting process; If all differences in the group are greater than 0, then the voltages corresponding to all the differences in the group are combined into a first data segment; if all differences in the group are less than 0, then the voltages corresponding to all the differences in the group are combined into a second data segment. The first and second data segments are sorted according to the time axis to obtain the segmented recovery sequence.

[0010] As a further aspect of the present invention: applying a positive voltage pulse further includes: Obtain the total number N of the first data segment and the second data segment, and set N as the number of stages in which the positive voltage pulse is applied this time; Obtain the number Di of the mid-terminal voltage of the first or second data segment at the i-th sorting position in the segmented recovery sequence, and obtain the number Dtot of the mid-terminal voltage of all the first and second data segments. Calculate the adjustment ratio Pi = Di / Dtot. Adjust the length Ti of the i-th pulse time segment in the pulse sorting to Pi multiplied by t, where t = T / N, and T represents the preset pulse width; Label the pulse periods according to the segmented recovery sequence. If the first data segment is at the i-th sorting position in the segmented recovery sequence, the label of the i-th pulse period is rising; if the second data segment is at the i-th sorting position in the segmented recovery sequence, the label of the i-th pulse period is falling.

[0011] As a further aspect of the present invention: applying a positive voltage pulse further includes: The pulse generating circuit includes a programmable voltage source, the positive terminal of which is connected to the positive terminal of the building rooftop energy storage battery, and the negative terminal of which is connected to the negative terminal of the building rooftop energy storage battery. After generating the pulse trigger command, an internal charging enable command is sent to the programmable voltage source. After receiving the internal charging enable command, the programmable voltage source closes the internal DC bus capacitor charging switch and begins sampling its internal DC bus voltage. When the internal DC bus voltage is greater than or equal to the preset internal target voltage, it is determined that the charging preparation is complete, and the programmable voltage source disconnects the charging switch of its internal DC bus capacitor. The terminal voltage of the building rooftop energy storage battery at this time is taken as the waveform start voltage V0, and the 0th pulse period is set as V0; If the tag for the i-th pulse period is rising, then the target voltage value V at the end of the i-th pulse period is... i =V i-1 +K, where K is a preset fixed voltage increment, V i-1 This represents the target voltage value at the end of the (i-1)th pulse period; If the tag for the i-th pulse period is decreasing, then the target voltage value V at the end of the i-th pulse period is... i =V i-1 -K; Calculate the time point at which the i-th pulse period ends: TENDi = T1 + T2 + ... + Ti; The voltage waveform instruction is formed by sequentially combining the end times of all pulse periods with the corresponding target voltage values. After receiving a voltage waveform command, the programmable voltage source generates a positive voltage pulse with a duration of T at its output terminal. During the i-th pulse phase, the programmable voltage source controls the voltage from V... i-1 Linear change to target voltage value V i .

[0012] A solar energy storage system for building rooftops includes: Generation module: During the discharge phase of the building rooftop energy storage battery, continuously monitor the real-time current value of the discharge circuit, and determine whether to generate a pulse trigger command based on the real-time current value and the state of charge of the building rooftop energy storage battery. Control module: In response to the pulse trigger command, it controls the discharge circuit of the building rooftop energy storage battery to be disconnected, and controls the pulse generation circuit to apply a positive voltage pulse between the positive and negative terminals of the building rooftop energy storage battery within a preset pulse width; After the positive voltage pulse ends, reconnect the discharge circuit of the building rooftop energy storage battery; Optimization module: Records the real-time current value, the state of charge of the building rooftop energy storage battery, and the amplitude and width data of the positive voltage pulse each time a positive voltage pulse is applied; The standard for determining whether to generate a pulse trigger command is based on the updated recorded data.

[0013] The beneficial effects of this invention compared to the prior art are as follows: This invention introduces a periodic pulse intervention process during the low-current discharge phase of an energy storage battery, enabling dynamic adjustment of the interface layer formed under prolonged low-current discharge conditions. By monitoring the discharge state in real time, a voltage pulse with adjustable stages and directions is applied when triggering conditions are met. This causes the battery terminal voltage to periodically rise or fall within a preset waveform, facilitating ion redistribution at the electrode interface and mitigating ion retention caused by prolonged low-current discharge. After the voltage pulse ends, normal discharge resumes, returning the battery to a stable output state. Simultaneously, relevant data is used to update the triggering criteria, ensuring the pulse application process continuously adapts to changes in battery state. Through this dynamic adjustment mechanism, this invention suppresses the non-uniform thickening trend of the interface layer, improves the ion migration environment on the electrode surface, and reduces the performance degradation rate caused by side reactions. This maintains the effective capacity of the energy storage battery during long-term operation and improves the stability and lifespan of rooftop solar energy storage systems under low-power nighttime operation conditions. Attached Figure Description

[0014] The invention will now be further described with reference to the accompanying drawings.

[0015] Figure 1 This is a schematic flowchart of a solar energy storage method for building rooftops according to the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 As shown, the present invention is a method for solar energy storage on building rooftops, comprising the following steps: During the discharge phase of the building rooftop energy storage battery, the real-time current value of the discharge circuit is continuously monitored, and a pulse trigger command is generated based on the real-time current value and the state of charge of the building rooftop energy storage battery. In a preferred embodiment of the present invention, determining whether to generate a pulse trigger command includes: Within a preset time window, real-time current values ​​are acquired at fixed sampling intervals, and the number of times the real-time current value is lower than the low current threshold within the time window is counted. When the number of attempts reaches the threshold and the state of charge of the building's rooftop energy storage battery is higher than the state of charge threshold at the end of the time window, a pulse trigger command is generated.

[0018] In response to a pulse trigger command, the discharge circuit of the building rooftop energy storage battery is disconnected, and the pulse generation circuit is controlled to apply a positive voltage pulse between the positive and negative terminals of the building rooftop energy storage battery within a preset pulse width. In a preferred embodiment of the present invention, applying a positive voltage pulse includes: After the positive voltage pulse of the previous cycle ends, the controller continuously reads the terminal voltage of the building rooftop energy storage battery according to the preset sampling interval. The sampling interval can be set to a fixed time step by the program parameters, so as to form voltage data points with a clear sequence on the time axis.

[0019] After acquiring a new terminal voltage, the controller compares it with the previous voltage data to determine the voltage difference between the two samples. All differences are automatically arranged in chronological order of sampling time, ensuring that subsequent processing strictly corresponds to the true time relationship of battery terminal voltage changes.

[0020] The grouping of differences is accomplished by traversing the sorted sequence of differences. Consecutive positive differences are grouped into one group, and consecutive negative differences are grouped into another. The condition for grouping differences is that each difference must be temporally adjacent to at least one difference within that group. This requirement ensures that the data within each group reflects the actual trend of continuous voltage increases or decreases. For example, if the controller continuously samples three sets of gradually increasing voltage values, the corresponding differences are all positive, and this will be automatically identified as a continuous increasing segment; if the continuously sampled voltage gradually decreases, the differences are all negative, and this will be considered a continuous decreasing segment.

[0021] When all differences in a group are positive, the controller extracts and sequentially combines the original terminal voltage points corresponding to these differences to form a first data segment, representing a continuous upward trend in voltage within that time region. When all differences are negative, a second data segment is formed in the same way, representing a continuous downward trend in voltage. After obtaining all the first and second data segments, the controller rearranges them according to the initial time sequence of these data segments to generate a segmented recovery sequence, ensuring that the position of each data segment in the sequence accurately reflects the evolution of the battery terminal voltage over time.

[0022] In another preferred embodiment of the present invention, applying a positive voltage pulse further includes: After constructing the segmented recovery sequence, the number of stages of the current positive voltage pulse needs to be determined based on the number of the first and second data segments contained in the sequence. The total number of data segments can be obtained directly by reading the length of the segmented recovery sequence. This total number is used as the number of stages required for the current positive voltage pulse, so that the stage division of the pulse can be consistent with the natural segments of voltage change.

[0023] After determining the number of stages, each sorting position in the segmented recovery sequence will be read item by item. At the first sorting position, the controller will retrieve the number of terminal voltages in the data segment corresponding to that position. This number represents the time span of continuous change of that segment during the recording process. Commonly, when the sampling frequency remains constant, the more terminal voltages there are, the longer the actual length of that segment.

[0024] The same search is performed on all data segments in the sequence to obtain the sum of all terminal voltage counts. A scaling factor is generated based on the ratio of this sum to the number of terminal voltage counts within a single segment, used to adjust the pulse duration. To ensure that the length of each pulse duration reflects the relative weight of its corresponding segment in the actual voltage change, the preset pulse width is divided into several equal parts using internal parameters. Each part represents a base duration, which is then scaled according to the aforementioned scaling factor. This allows the actual pulse duration to change with the number of terminal voltage counts in the data segment. For example, when a segment in the segmented recovery sequence contains a relatively large number of terminal voltage counts, the corresponding pulse duration is lengthened, making the voltage change within that segment smoother. When the number of terminal voltage counts is small, the corresponding pulse duration is shortened accordingly, making the overall waveform more closely match the actual trend of battery terminal voltage changes during the sampling process.

[0025] After adjusting the pulse duration, a label needs to be assigned to each pulse duration. This is achieved by reading the data segment type at that sorting position in the segmented recovery sequence. When the data segment at that sorting position originates from the first data segment, the controller marks the corresponding pulse duration as rising, enabling subsequent voltage control logic to identify that the output voltage needs to be increased to the next target voltage in this stage. When the data segment at that sorting position originates from the second data segment, the corresponding pulse duration is marked as falling, enabling subsequent voltage control logic to identify that the output voltage needs to be decreased to the next target voltage in this stage. Through this process, the required number of stages, the duration of each stage, and the voltage change direction of each stage are fully constructed, providing an accurate structural basis for subsequently generating a linear voltage change waveform.

[0026] In a preferred embodiment, applying the positive voltage pulse further includes: The positive terminal of the programmable voltage source is fixedly connected to the positive terminal of the building rooftop energy storage battery, and the negative terminal of the output terminal is fixedly connected to the negative terminal of the energy storage battery. Through this direct connection method, the programmable voltage source can stably apply a preset voltage waveform to both ends of the energy storage battery after being triggered.

[0027] Upon receiving a pulse trigger command, the controller sends an internal charging enable command to the programmable voltage source. This command is transmitted to the voltage source via the communication bus, causing the voltage source to enter a pre-charging state in preparation for outputting a voltage pulse. Upon receiving the charging enable command, the voltage source closes its internal DC bus capacitor charging switch, forming a rechargeable circuit between the bus capacitor and the DC power supply section of the voltage source. It then begins automatically sampling the bus voltage, reading its changes in real time through an internal sampling module. The bus voltage gradually increases during charging. When the bus voltage reaches the preset internal target voltage, the control logic determines that charging preparation is complete. At this point, it immediately disconnects the DC bus capacitor charging switch, maintaining the bus capacitor at a stable voltage state after charging, providing the necessary energy for subsequent voltage pulse generation.

[0028] After preparation is complete, it is necessary to determine the starting value of the voltage waveform. The starting voltage is obtained by reading the terminal voltage of the energy storage battery at this time and set as the starting point of the pulse sequence. At the same time, the output value of the zeroth pulse period is set as this starting voltage so that each subsequent pulse period can transition under this starting reference.

[0029] Subsequently, the controller reads the tag for each pulse period in sequence. When the tag is rising, the target voltage for the current period is determined by adding a preset fixed voltage increment to the target voltage at the end of the previous period. This increment is set in the device parameter configuration to ensure that the voltage increase is consistent in each rising period. When the tag is falling, the target voltage for the current period is determined by reducing the same fixed voltage increment from the target voltage at the end of the previous period, so that the voltage shows a uniform decreasing trend during the falling period.

[0030] To precisely control the output process of each pulse period, it is necessary to calculate the end time of each period. The end time of each period is obtained by sequentially summing the lengths of each period, ensuring that the overall waveform accurately corresponds to the previously calculated period division on the time axis. After determining the time and voltage points, the controller combines the end times of all pulse periods with their corresponding target voltage values ​​to form a complete voltage waveform command sequence. This sequence is arranged in chronological order and can describe the complete path of voltage change throughout the entire pulse duration.

[0031] Upon receiving the voltage waveform command, the programmable voltage source uses its internal digital control algorithm to smoothly transition the voltage from the previous target value to the current target value in a linear manner within each time period. For example, during a rising phase, the voltage source gradually increases the output voltage within a specified time interval of that phase, raising it from the voltage value at the end of the previous time period to the newly set target value, while maintaining the continuity of the overall change curve. During the falling phase, the voltage source gradually decreases the output voltage to the target value in the same manner. The total duration of the entire process is consistent with the preset pulse width, thereby applying a positive voltage pulse to the energy storage battery, allowing the voltage curve to change in an orderly manner according to the previously constructed segmented recovery sequence.

[0032] After the positive voltage pulse ends, reconnect the discharge circuit of the building rooftop energy storage battery; Record the real-time current value, the state of charge of the building rooftop energy storage battery, and the amplitude and width data of the positive voltage pulse each time a positive voltage pulse is applied; In a preferred embodiment of the present invention, a standard for determining whether to generate a pulse trigger command is updated based on recorded data.

[0033] The updated criteria for determining whether to generate a pulse trigger command include: The average of the recorded real-time current values ​​is calculated and used as the updated low current threshold. Obtain the maximum value A1 and minimum value A2 from the recorded states of charge, and obtain the new state of charge threshold Y1=Y+(A1+A2) / 2, where Y represents the current state of charge threshold.

[0034] It is worth noting that during long-term low-current discharge, the internal state of the energy storage battery does not remain static, but constantly changes with slight fluctuations in load, battery temperature, electrode interface conditions, and ion migration efficiency. A fixed judgment threshold cannot accurately reflect the battery's true operating characteristics over a long period. Therefore, it is necessary to dynamically calibrate the judgment conditions using data actually recorded during discharge. The average level of real-time current values ​​reflects the typical operating current of the battery during recent discharge. When the battery's low-current range changes, the average value is adjusted accordingly. This allows the new low-current threshold to better match the actual current distribution of the current discharge stage, thus making the trigger judgment adaptive. The maximum and minimum values ​​of the state of charge reflect the actual energy range of the battery within the recording period. By correlating the current state of charge threshold with these two extreme values, the updated threshold can be closer to the typical energy level of the battery within that period, allowing the benchmark for judging the trigger timing to adjust with the natural fluctuations of the battery state. The principle behind this update method is that by recalibrating the threshold using data reflecting the battery's true operating state, the judgment conditions no longer rely on fixed static parameters, but can automatically adapt to the actual performance of the battery in different operating stages, making the trigger logic more consistent with the battery's current response characteristics in subsequent cycles. This adaptive mechanism ensures that the voltage pulse is always triggered within a range that can influence changes in the electrode interface. This helps to make the pulse intervention process act more stably on the battery interface layer state, providing continuous and more matched regulation to maintain the ion migration environment of the electrode interface. This helps the overall scheme achieve the goal of interface stability control during long-term operation.

[0035] It is important to note that by monitoring changes in battery terminal voltage and real-time current under low-current discharge conditions, signs of restricted ion migration at the electrode interface can be identified. When certain conditions are met, a positive voltage pulse is applied in a timely manner, allowing the battery electrode interface to reform a more uniform ion distribution environment under the influence of the pulse. Dynamically updating the threshold ensures that the triggering logic continuously matches the actual state changes of the battery, preventing the pulse application from being premature or delayed. The pulse waveform is constructed based on the natural trend of terminal voltage changes in previous cycles. A segmented approach ensures that the pulse voltage changes are consistent with the actual battery performance, allowing the electrode interface to gradually alleviate ion accumulation through a continuous linear increase or decrease, reducing interface layer accumulation and electrolyte consumption caused by ion retention. This solution, through periodic voltage regulation during discharge, keeps the battery interface layer in a dynamic migration state, fundamentally improving the trend of abnormal interface layer thickening under low-current discharge conditions, thus maintaining a more stable capacity performance of the energy storage battery during long-term operation.

[0036] The proposed solution introduces a pulse triggering mechanism that dynamically adjusts based on changes in the battery's actual state under low-current discharge conditions. This ensures that the timing of voltage pulse intervention aligns with the actual rhythm of ion distribution and interface layer evolution at the electrode interface, creating an interface intervention method that adaptively adjusts to changes in battery state. The voltage pulse waveform is not a simple fixed slope or amplitude; instead, it generates a segmented recovery sequence based on the natural trend of the terminal voltage within the previous cycle. The number of pulse stages, stage length, and voltage rise / fall direction are dynamically constructed based on this sequence, allowing the voltage regulation behavior applied to the battery to more closely resemble the battery's intrinsic response. This voltage intervention structure, shaped based on the battery's own operational records, compared to traditional methods that rely solely on a single fixed parameter to determine triggering timing or use a single waveform to stimulate the battery, can create a regulation process that better conforms to the battery's interface dynamics in a stable discharge environment. This promotes the maintenance of an active ion distribution at the electrode interface, thereby delaying abnormal interface layer thickening and maintaining effective capacity.

[0037] A solar energy storage system for building rooftops includes: Generation module: During the discharge phase of the building rooftop energy storage battery, continuously monitor the real-time current value of the discharge circuit, and determine whether to generate a pulse trigger command based on the real-time current value and the state of charge of the building rooftop energy storage battery. Control module: In response to the pulse trigger command, it controls the discharge circuit of the building rooftop energy storage battery to be disconnected, and controls the pulse generation circuit to apply a positive voltage pulse between the positive and negative terminals of the building rooftop energy storage battery within a preset pulse width; After the positive voltage pulse ends, reconnect the discharge circuit of the building rooftop energy storage battery; Optimization module: Records the real-time current value, the state of charge of the building rooftop energy storage battery, and the amplitude and width data of the positive voltage pulse each time a positive voltage pulse is applied; The standard for determining whether to generate a pulse trigger command is based on the updated recorded data.

[0038] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for solar energy storage on building rooftops, characterized in that, Includes the following steps: During the discharge phase of the building rooftop energy storage battery, the real-time current value of the discharge circuit is continuously monitored, and a pulse trigger command is generated based on the real-time current value and the state of charge of the building rooftop energy storage battery. In response to a pulse trigger command, the discharge circuit of the building rooftop energy storage battery is disconnected, and the pulse generation circuit is controlled to apply a positive voltage pulse between the positive and negative terminals of the building rooftop energy storage battery within a preset pulse width. After the positive voltage pulse ends, reconnect the discharge circuit of the building rooftop energy storage battery; Record the real-time current value, the state of charge of the building rooftop energy storage battery, and the amplitude and width data of the positive voltage pulse each time a positive voltage pulse is applied; The standard for determining whether to generate a pulse trigger command based on updated recorded data; Determining whether to generate a pulse trigger command includes: Within a preset time window, real-time current values ​​are acquired at fixed sampling intervals, and the number of times the real-time current value is lower than the low current threshold within the time window is counted. When the number of attempts reaches the threshold and the state of charge of the building's rooftop energy storage battery is higher than the state of charge threshold at the end of the time window, a pulse trigger command is generated. The updated criteria for determining whether to generate a pulse trigger command include: The average of the recorded real-time current values ​​is calculated and used as the updated low current threshold. Obtain the maximum value A1 and minimum value A2 from the recorded states of charge, and obtain the new state of charge threshold Y1=Y+(A1+A2) / 2, where Y represents the current state of charge threshold.

2. The method for solar energy storage on building rooftops according to claim 1, characterized in that, Applying a positive voltage pulse includes: After the last positive voltage pulse is applied, the terminal voltage of the building rooftop energy storage battery is acquired at a preset sampling interval, the difference between two adjacent terminal voltages is calculated, and the difference is sorted in order of time axis. Group the differences, where all differences in a single group are greater than 0 or all differences are less than 0, and the difference j in a group is adjacent to at least one difference in the same group in the sorting process; If all differences in the group are greater than 0, then the voltages corresponding to all the differences in the group are combined into a first data segment; if all differences in the group are less than 0, then the voltages corresponding to all the differences in the group are combined into a second data segment. The first and second data segments are sorted according to the time axis to obtain the segmented recovery sequence.

3. A method for solar energy storage on building rooftops according to claim 2, characterized in that, Applying a positive voltage pulse also includes: Obtain the total number N of the first data segment and the second data segment, and set N as the number of stages in which the positive voltage pulse is applied this time; Obtain the number Di of the mid-terminal voltage of the first or second data segment at the i-th sorting position in the segmented recovery sequence, and obtain the number Dtot of the mid-terminal voltage of all the first and second data segments. Calculate the adjustment ratio Pi = Di / Dtot. Adjust the length Ti of the i-th pulse time segment in the pulse sorting to Pi multiplied by t, where t = T / N, and T represents the preset pulse width; Label the pulse periods according to the segmented recovery sequence. If the first data segment is at the i-th sorting position in the segmented recovery sequence, the label of the i-th pulse period is rising; if the second data segment is at the i-th sorting position in the segmented recovery sequence, the label of the i-th pulse period is falling.

4. A method for solar energy storage on building rooftops according to claim 3, characterized in that, Applying a positive voltage pulse also includes: The pulse generating circuit includes a programmable voltage source, the positive terminal of which is connected to the positive terminal of the building rooftop energy storage battery, and the negative terminal of which is connected to the negative terminal of the building rooftop energy storage battery. After generating the pulse trigger command, an internal charging enable command is sent to the programmable voltage source. After receiving the internal charging enable command, the programmable voltage source closes the internal DC bus capacitor charging switch and begins sampling its internal DC bus voltage. When the internal DC bus voltage is greater than or equal to the preset internal target voltage, it is determined that the charging preparation is complete, and the programmable voltage source disconnects the charging switch of its internal DC bus capacitor. The terminal voltage of the building rooftop energy storage battery at this time is taken as the waveform start voltage V0, and the 0th pulse period is set as V0; If the tag for the i-th pulse period is rising, then the target voltage value V at the end of the i-th pulse period is... i =V i-1 +K, where K is a preset fixed voltage increment, V i-1 This represents the target voltage value at the end of the (i-1)th pulse period; If the tag for the i-th pulse period is decreasing, then the target voltage value V at the end of the i-th pulse period is... i =V i-1 -K; Calculate the time point at which the i-th pulse period ends: TENDi = T1 + T2 + ... + Ti; The voltage waveform instruction is formed by sequentially combining the end times of all pulse periods with the corresponding target voltage values. After receiving a voltage waveform command, the programmable voltage source generates a positive voltage pulse with a duration of T at its output terminal. During the i-th pulse phase, the programmable voltage source controls the voltage from V... i-1 Linear change to target voltage value V i .

5. A solar energy storage system for building rooftops, characterized in that, include: Generation module: During the discharge phase of the building rooftop energy storage battery, continuously monitor the real-time current value of the discharge circuit, and determine whether to generate a pulse trigger command based on the real-time current value and the state of charge of the building rooftop energy storage battery. Control module: In response to the pulse trigger command, it controls the discharge circuit of the building rooftop energy storage battery to be disconnected, and controls the pulse generation circuit to apply a positive voltage pulse between the positive and negative terminals of the building rooftop energy storage battery within a preset pulse width; After the positive voltage pulse ends, reconnect the discharge circuit of the building rooftop energy storage battery; Optimization module: Records the real-time current value, the state of charge of the building rooftop energy storage battery, and the amplitude and width data of the positive voltage pulse each time a positive voltage pulse is applied; The standard for determining whether to generate a pulse trigger command based on updated recorded data; Determining whether to generate a pulse trigger command includes: Within a preset time window, real-time current values ​​are acquired at fixed sampling intervals, and the number of times the real-time current value is lower than the low current threshold within the time window is counted. When the number of attempts reaches the threshold and the state of charge of the building's rooftop energy storage battery is higher than the state of charge threshold at the end of the time window, a pulse trigger command is generated. The updated criteria for determining whether to generate a pulse trigger command include: The average of the recorded real-time current values ​​is calculated and used as the updated low current threshold. Obtain the maximum value A1 and minimum value A2 from the recorded states of charge, and obtain the new state of charge threshold Y1=Y+(A1+A2) / 2, where Y represents the current state of charge threshold.

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