Coordination method and system for power smoothing and peak load shifting of optical storage system

Abstract

The invention provides a coordination method and system for power smoothing and peak clipping and valley filling of an optical storage system, and the method comprises the steps: determining a symmetric available power amplitude and a charge state available operation boundary at the beginning of each operation cycle; dynamically generating a single-side charge state change limit capable of being occupied by grid-connected power smoothness and a single-side charge state change limit capable of being occupied by peak load shifting in the period; converting a single-side charge state change limit which can be occupied by grid-connected power smoothing and a single-side charge state change limit which can be occupied by peak clipping and valley filling in the current period into a power smoothing suppression factor of a power smoothing instruction in the current control period; the state interval is allowed to be occupied in the peak load shifting charging direction and the state interval is allowed to be occupied in the peak load shifting discharging direction; and in each control period, a final energy storage charging and discharging power instruction is generated and executed. According to the method, coordinated and consistent operation of power smoothing and peak load shifting is achieved on the equipment level, and control continuity and engineering feasibility under the complex working condition are improved.

Description

Technical Field

[0001] This invention belongs to the field of power smoothing and peak shaving in photovoltaic energy storage systems, and particularly relates to a coordinated method and system for power smoothing and peak shaving in photovoltaic energy storage systems. Background Technology

[0002] With the large-scale integration of photovoltaic (PV) power generation into distribution networks and user sides, PV output exhibits random fluctuations and rapid ramp-up characteristics due to factors such as cloud cover, irradiance, and temperature. Coupled with random changes on the load side, this easily leads to power fluctuations and exceeding ramp-up limits at the grid connection point, subsequently inducing power quality problems such as voltage fluctuations. In engineering practice, energy storage is often used in conjunction with PV. Energy storage charging and discharging compensation achieves grid-connected power smoothing, and over longer timescales, energy storage is used for energy transfer to achieve peak shaving and valley filling, improving operational economics.

[0003] Existing solutions typically develop control strategies at different time scales. The real-time layer focuses on suppressing short-term fluctuations, while the planning layer focuses on peak-valley energy scheduling. These two are often coordinated through priorities, weights, or empirical thresholds. In actual power plant operation, this coordination method often reveals structural contradictions: power smoothing and peak shaving / valley filling consume the same energy storage resources simultaneously, constrained by both charging and discharging power limits and available state-of-charge space. Furthermore, their consumption methods differ: smoothing exhibits frequent, small-amplitude, bidirectional adjustments, while peak shaving / valley filling is continuous, unidirectional, and occupies a larger state space. When grid connection fluctuations increase, peak shaving / valley filling targets become urgent, or equipment-side power limits tighten, energy storage is more likely to approach the state boundary during real-time smoothing. Control commands may exhibit passive limiting, frequent edge-touching, and abrupt changes in control strength, affecting grid-connected power stability and potentially hindering the implementation of peak shaving / valley filling plans. Conversely, if the planning layer excessively pre-occupies state space, it will compress the available margin for real-time smoothing, making it difficult to suppress grid-connected power deviations in a timely manner.

[0004] Furthermore, many engineering implementations only use fixed upper and lower limits of state of charge or fixed power limits as constraints, lacking a mechanism to explicitly define the "range of state changes that can be achieved within this operating cycle". This results in the boundary of available resources occupied by different control objectives being passively exposed only during execution. Strategy adjustments often manifest as abrupt switching or repeated corrections, making it difficult to maintain control continuity and coordination under complex operating conditions.

[0005] Therefore, there is an urgent need for a coordination method and system that is oriented towards the actual executable capabilities of photovoltaic and energy storage systems, which can simultaneously support grid-connected power smoothing and peak shaving and valley filling under unified constraints, and maintain continuous controllability of instructions and clear division of labor when approaching resource boundaries. Summary of the Invention

[0006] The purpose of this invention is to propose a coordinated method and system for power smoothing and peak shaving in photovoltaic energy storage systems, thereby solving the aforementioned problems.

[0007] To achieve the above objectives, a first aspect of the present invention provides a coordinated method for power smoothing and peak shaving / valley filling in a photovoltaic-storage system, the method comprising the following steps: S1. At the beginning of each operating cycle, based on the maximum charging power and maximum discharging power of the energy storage system, determine the symmetrical available power amplitude and the available operating boundary of the state of charge of the energy storage system in the current operating cycle. S2. Within the available operating boundary of the state of charge, based on the symmetrical available power amplitude of the energy storage system and the total window width based on the available operating boundary of the state of charge, dynamically generate the single-sided state of charge change quota available for grid-connected power smoothing in this cycle and the single-sided state of charge change quota available for peak shaving and valley filling in this cycle. S3. The single-sided state-of-charge change allowance available for grid-connected power smoothing in this cycle and the single-sided state-of-charge change allowance available for peak shaving and valley filling in this cycle are converted into the power smoothing suppression factor, the allowed state interval for peak shaving and valley filling charging direction, and the allowed state interval for peak shaving and valley filling discharging direction of the power smoothing command in the current control cycle; wherein, the power smoothing suppression factor of the power smoothing command in the current control cycle is a continuous suppression rule based on the remaining margin, used for the amplitude convergence of the power smoothing command; the allowed state interval for peak shaving and valley filling charging direction and the allowed state interval for peak shaving and valley filling discharging direction are directional constraint rules based on interval determination, used for the permissibility determination of the peak shaving and valley filling command; S4. In each control cycle, the original adjustment requirements are confirmed based on the current grid-connected power deviation. At the same time, the continuous suppression rule and / or the directional constraint rule are applied to generate and execute the final energy storage charging and discharging power command, taking into account the current operating stage and energy storage state of charge.

[0008] Furthermore, determining the symmetrical available power amplitude and available state of charge operating boundary of the energy storage system within the current operating cycle specifically involves: Obtain the state of charge of the energy storage system at the start of the current operating cycle; Obtain the maximum charging power and maximum discharging power of the energy storage converter of the energy storage system under the current operating conditions, and take the smaller of the two values ​​as the symmetrical available power amplitude used in this operating cycle; Based on the symmetrical available power amplitude used in this operating cycle, the duration of the operating cycle, and the available energy capacity of the energy storage system, the maximum state of charge change amplitude that the energy storage system can achieve under the power limit constraint within the cycle is calculated. Using the state of charge at the start of the operating cycle as the center and the maximum state of charge change amplitude as the unilateral offset, the usable operating boundary of the state of charge is determined.

[0009] Furthermore, the single-sided state of charge change quota that can be used for dynamic generation of grid-connected power smoothing in this cycle and the single-sided state of charge change quota that can be used for peak shaving and valley filling in this cycle are specifically as follows: Based on the symmetrical available power amplitude and the rated power amplitude of the energy storage converter, the power regulation capability strength index is determined. Based on the available operating boundary of the state of charge, determine the total window width of the state of charge that can change within this cycle; Combining the power regulation capability strength index, the total window width of the variable state of charge in this cycle, and the pre-configured reference proportional coefficient, the proportional coefficient allocated to grid-connected power smoothing in this cycle is calculated. According to the above, the total state change space corresponding to the available operating boundary of the state of charge is divided into the single-sided state of charge change quota that can be occupied by grid-connected power smoothing in this cycle and the single-sided state of charge change quota that can be occupied by peak shaving and valley filling in this cycle.

[0010] Furthermore, the scaling factor is implemented through a saturation operator: When the value inside the parentheses of the saturation operator is less than 0, it takes the value 0; when it is greater than 1, it takes the value 1; otherwise, it takes the original value.

[0011] Furthermore, the conversion step of the power smoothing suppression factor of the power smoothing command in the current control cycle includes: With the state of charge saved at the start of the current operating cycle as the center and the unilateral state of charge change limit that can be occupied by the grid-connected power smoothing in this cycle as the radius, a core state interval that the power smoothing can allow is constructed. In each control cycle, calculate the remaining margin from the current state of charge to the boundary of the core state interval; Based on the remaining margin, the power smoothing suppression factor of the power smoothing command in the current control cycle is obtained by normalizing according to the preset scale parameter; wherein, when the remaining margin is sufficient, the power smoothing suppression factor is close to 1, and the command is not suppressed; when the remaining margin decreases, the power smoothing suppression factor decreases continuously, and the command amplitude is smoothed and compressed.

[0012] Furthermore, the power smoothing suppression factor is a segmental linear function, and combined with the saturation operator commonly used in control engineering, it ensures that the result is always between 0 and 1.

[0013] Furthermore, the conversion steps for the allowed state intervals in the peak-shaving and valley-filling charging direction and the allowed state intervals in the peak-shaving and valley-filling discharging direction include: Based on the core state interval and the single-sided state of charge change limit that can be occupied for peak shaving and valley filling in this cycle, state intervals that can be occupied in the charging direction and the discharging direction for peak shaving and valley filling are respectively constructed outside the core state interval.

[0014] Furthermore, the directional constraint rule, used for the permissibility determination of peak-shaving and valley-filling instructions, specifically includes: When peak shaving and valley filling charging is required, a corresponding charging command is only allowed to be generated if the current state of charge falls within the state range that is allowed to be occupied in the peak shaving and valley filling charging direction; when peak shaving and valley filling discharging is required, a corresponding discharging command is only allowed to be generated if the current state of charge falls within the state range that is allowed to be occupied in the peak shaving and valley filling discharging direction.

[0015] Furthermore, the generation of the final energy storage charging and discharging power command specifically involves: During the power smoothing phase, the final energy storage charging and discharging power command is calculated based on the original adjustment demand and the power smoothing suppression factor obtained from the current control cycle; wherein, the original adjustment demand is the current grid-connected power deviation between the current grid-connected power and the target grid-connected power reference value; During the peak shaving and valley filling implementation phase First, determine whether the direction of the current grid-connected power deviation falls within the state range that is allowed to be occupied in the peak-shaving and valley-filling charging direction and the state range that is allowed to be occupied in the peak-shaving and valley-filling discharging direction: If the current grid-connected power deviation is less than 0, it is determined to be the charging direction and the state interval allowed to be occupied by the peak shaving and valley filling charging direction is selected. If the current grid-connected power deviation is greater than 0, it is determined to be the discharge direction and the state interval allowed to be occupied by the peak-shaving and valley-filling discharge direction is selected. If the current grid-connected power deviation is equal to 0, then the energy storage charging and discharging power command generated in the current control cycle is directly set as the current grid-connected power deviation. Then compare whether the current state of charge falls within the selected state range: If the current state of charge falls into the corresponding selected state interval, the energy storage charging and discharging power command generated in the current control cycle is set as the current grid-connected power deviation and is issued for execution; If the current state of charge does not fall into the corresponding selected state interval, the energy storage charging and discharging power command generated in the current control cycle is made to be the product of the current grid-connected power deviation and the power smoothing suppression factor, and is issued and executed according to the power smoothing path.

[0016] In a second aspect of the invention, a coordinated system for power smoothing and peak shaving / valley filling in a photovoltaic energy storage system is provided, the system comprising: The boundary management module is used to determine the symmetrical available power amplitude and available state of charge operating boundary of the energy storage system at the beginning of each operating cycle, based on the maximum charging power and maximum discharging power of the energy storage system in the current operating cycle. The quota allocation module is used to dynamically generate the single-sided state-of-charge change quota available for grid-connected power smoothing and the single-sided state-of-charge change quota available for peak shaving and valley filling in the current cycle, based on the symmetrical available power amplitude of the energy storage system and the total window width based on the available state-of-charge operation boundary within the state-of-charge available operating boundary. The rule generation module is used to convert the single-sided state-of-charge change (SOC) allowance available for grid-connected power smoothing in the current cycle and the single-sided SOC allowance available for peak shaving and valley filling in the current cycle into a power smoothing suppression factor, a permissible state interval for peak shaving and valley filling charging, and a permissible state interval for peak shaving and valley filling discharging in the current control cycle. The power smoothing suppression factor for the power smoothing command in the current control cycle is a continuous suppression rule based on residual margin, used for amplitude convergence of the power smoothing command. The permissible state intervals for peak shaving and valley filling charging and discharging are directional constraint rules based on interval determination, used for permissibility judgment of peak shaving and valley filling commands. The instruction coordination and execution module is used to confirm the original adjustment requirements based on the current grid-connected power deviation in each control cycle, and at the same time, combine the current operating stage and the energy storage state of charge, apply the continuous suppression rule and / or the directional constraint rule, generate the final energy storage charging and discharging power instruction and execute it.

[0017] The beneficial technical effects of the present invention are at least as follows: This invention constructs a coordinated control framework based on the actual executable capability of grid-connected operation of photovoltaic-storage systems. It solidifies the available capacity of energy storage within the operating cycle into a stable operating boundary in a calculable manner. Within this boundary, it explicitly classifies the resource usage of grid-connected power smoothing and peak shaving / valley filling into two categories of behavioral limits. This quantifies and controls the usage relationship of the same energy storage resources by different objectives at the beginning of the operating cycle. Building upon this, the invention further transforms these behavioral limits into directly invoked constraint rules for command generation. By continuously converging the smoothing control strength as the state approaches the boundary, and by limiting the feasibility of peak shaving / valley filling energy transfer through directional state intervals, it achieves hierarchical usage and non-crowding of smoothing and peak shaving / valley filling within the same state space. Finally, this invention integrates the power command generation driven by grid-connected power deviation with the aforementioned constraint rules, forming a unique and executable energy storage charging and discharging power command in each control cycle and issuing it to the energy storage converter for execution. This allows grid-connected power fluctuations to be effectively suppressed under rule constraints, while peak shaving and valley filling complete energy transfer within the reserved state space. This achieves coordinated operation of power smoothing and peak shaving and valley filling at the equipment level, and improves control continuity and engineering feasibility under complex operating conditions. Attached Figure Description

[0018] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0019] Figure 1 This is a flowchart of a coordinated method for power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to the present invention. Detailed Implementation

[0020] 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.

[0021] like Figure 1 As shown in the figure, an embodiment of the present invention provides a coordinated method for power smoothing and peak shaving / valley filling in a photovoltaic-storage system, the method comprising: S1. At the beginning of each operating cycle, based on the maximum charging power and maximum discharging power of the energy storage system, determine the symmetrical available power amplitude and the available operating boundary of the state of charge of the energy storage system in the current operating cycle.

[0022] Specifically, this step is executed at the beginning of each operating cycle. Its purpose is to establish a stable energy storage state change boundary based on the current operating state of the photovoltaic-energy storage system throughout the entire operating cycle. This boundary is used to constrain all charging and discharging control behaviors during subsequent power smoothing and peak shaving. This boundary is directly derived from the real-time operating information provided by the field equipment of the energy storage system, and its result can accurately reflect the actual available capacity of the energy storage system within this operating cycle under the current operating conditions.

[0023] In the specific implementation process, at the start of the operating cycle, the energy management system reads the current state of charge of the energy storage system from the battery management system through the field communication interface. This state of charge is continuously calculated by the battery management system based on fundamental measurements such as the battery pack's voltage and current, and is periodically updated as an operating status variable. Simultaneously, the energy management system obtains the maximum allowable charging power under the current operating conditions through the control interface of the energy storage converter. and maximum discharge power The aforementioned power limits are determined in real time by the energy storage converter based on its own operating status, grid connection conditions, and internal protection strategies, and are provided externally through standardized measurement points or registers. In addition, the nominal available energy capacity of the energy storage system... The parameters are provided by the system configuration parameters, which are determined during the system commissioning or testing phase. These parameters characterize the energy storage system's dispatchable capacity under normal operating conditions; the duration of the operating cycle. The time scale is directly provided by the scheduling cycle configuration of the energy management system and serves as the time scale required for calculating state changes within the cycle.

[0024] Based on the above inputs, this step first unifies the charging and discharging power limits given by the energy storage converter, and takes the maximum charging power. With maximum discharge power The smaller value in the range is used as the symmetrical available power amplitude for this operating cycle. This processing method ensures that subsequent control commands, whether in the charging or discharging direction, are constrained by the same power amplitude, thus avoiding the introduction of inconsistent available capability boundaries in different directions. Subsequently, this is combined with the duration of the operating cycle. With the nominal available energy capacity of the energy storage system This maps the symmetrical available power amplitude to the maximum possible offset of the energy storage state of charge during the operating cycle. The calculation relationship is as follows:

[0025] in, This indicates the symmetrical available power amplitude used within this operating cycle; Indicates the duration of the running cycle; This indicates the nominal available energy capacity of the energy storage system; This represents the maximum change in state of charge (SOC) that the energy storage system can achieve under power limits during the operating cycle. The engineering implication of this relationship is that even if the energy storage system continuously charges or discharges at its maximum permissible power throughout the entire operating cycle, its SOC change will not exceed [a certain value]. The corresponding range.

[0026] To obtain the maximum state of charge offset Then, the state of charge at the start of the operating cycle. Centered on this, construct the usable operating boundary of the energy storage system's state of charge during this operating cycle. Its expression is:

[0027] in, This indicates the range within which the state of charge of the energy storage system is allowed to change during the current operating cycle. This range defines the physically achievable range of state changes in the energy storage system within the current operating cycle, and all subsequent control commands involving energy storage charging and discharging must be executed within this range.

[0028] As a preferred embodiment, the above calculation process can be more intuitively understood by considering a typical operating scenario. For example, at the beginning of a certain operating cycle, the battery management system reads the state of charge of the energy storage system as follows: The maximum charging power read through the energy storage converter interface is The maximum discharge power is The nominal available energy capacity configured in the system is The duration of the running cycle is Under this condition, the available power amplitude for symmetry is Further calculations yielded Thus, the operating boundary can be used for The results indicate that, within the current operating cycle, the range of state of charge variation of the energy storage system will be stably limited within this range, and will not exceed this boundary regardless of the specific charging and discharging strategy adopted in subsequent control.

[0029] S2. Within the available operating boundary of the state of charge, based on the symmetrical available power amplitude of the energy storage system and the total window width based on the available operating boundary of the state of charge, dynamically generate the single-sided state of charge change quota available for grid-connected power smoothing in this cycle and the single-sided state of charge change quota available for peak shaving and valley filling in this cycle.

[0030] Specifically, this step is performed at the beginning of the operating cycle, directly receiving the energy storage availability operating boundary output from step one. With symmetrical available power amplitude The system divides the "available state window for this cycle" into two types of executable behavior quotas: quotas for grid-connected power smoothing and quotas for peak shaving and valley filling. The implementation idea is derived from the "budget allocation" method in classical control and resource allocation. This involves first determining the total budget, then using an allocation coefficient constrained by a range to allocate the total budget to different uses. The allocation coefficient employs a saturation operator commonly used in control theory to limit the value within a specified range, ensuring that the allocation result always falls within the executable range. Unlike common fixed-ratio allocation, this step incorporates both the current available power of the converter and the width of the state window for this cycle into the allocation coefficient. This causes the smoothing and peak shaving quotas to change with operating conditions: when the power regulation capability is stronger and the state window is wider, the proportion of the smoothing quota increases; when the power regulation capability is weaker or the state window is narrower, the proportion automatically converges, thus forming a stable and clear quota boundary within the same operating cycle, facilitating the direct limitation of subsequent instruction generation.

[0031] The allocation coefficients are constructed based on two dimensionless indices. The first is the power regulation capability strength index. ,in The rated power amplitude of the energy storage converter is based on parameters from the equipment nameplate or commissioning parameter table and is embedded in the energy management system configuration items; symmetrical available power amplitude. The first output is the power limit reported by the converter at the start of the operating cycle, after symmetry processing. The second is the state window width index. ,in All are from the output of step one. This represents the total window width through which the state of charge can vary within the current cycle. The allocation coefficients adopt an affine structure of "baseline value + operating condition correction," with the operating condition correction term written as... This means that when the combined level of power intensity and window width is higher than a certain neutral level, a positive correction is made to the smoothing ratio; otherwise, a negative correction is made. The result is then cropped using a saturation operator. Within the interval. The corresponding calculation formula is:

[0032] in, This is the proportional coefficient allocated to grid-connected power smoothing in this cycle; This is a saturation operator in classical control, implemented as follows: when the value within the parentheses is less than... Time to take greater than Time to take The rest retain their original values; The pre-configured baseline ratio coefficient is set by the operation and maintenance personnel in the energy management system parameter table during engineering, and is used to reflect the station's preference for smoothing and peak shaving under normal operating conditions; The pre-configured sensitivity coefficient, also set by the parameter table, is used to adjust the magnitude of the operating condition correction. , , All are from the output of step one; From device configuration parameters. In this formula... and All are ratios or interval width indicators, and are dimensionless as a whole; therefore, the values ​​in parentheses are not necessarily related to the interval width. similar, It is also a dimensionless proportionality coefficient, satisfying common sense. The width of the state window is divided using this proportionality coefficient. At that time, the main window is divided into two sides in a "symmetrically available around the current state" manner, therefore... First, halve the total available credit limit for one side, then... and The credit limits are allocated separately to smoothing and peak shaving / valley filling, resulting in two types of behavioral credits:

[0033] in, The available single-sided state-of-charge (SOC) change allowance for grid-connected power smoothing during this cycle. The amount of single-sided state of charge variation that can be used for peak shaving and valley filling in this cycle; Output the window width for the boundary in step one; The result is obtained from the previous equation. The right sides of both equations are derived from the combination of a dimensionless proportionality coefficient and a dimensionless window width. The result is similar to the change in state of charge, and logically, it is first obtained from the previous equation. Substituting these values ​​into the formula yields two types of quotas, forming a clear derivation chain.

[0034] As a preferred embodiment, a complete substitution calculation can be completed within a typical operating cycle, based on the proportional value and configuration parameters. Let the output of step one be... ,but , Window width Step 1 output power amplitude meets ,Right now Energy management system configuration parameters are taken , Substituting into the distribution coefficient formula, we get the value in parentheses as follows: After the saturation operator is applied Substituting this into the quota allocation formula, we get... , The resulting two types of behavioral limits are output as the calculation results of this step: Used to constrain the occupancy of the state window by subsequent grid-connected power smoothing related control. This is used to constrain the occupancy of the state window by subsequent peak shaving and valley filling related controls; both calculations are based on the output of step one. and Driven and configured by device parameters With the running parameter table Complete the executable scaling mapping.

[0035] S3. The single-sided state-of-charge change allowance available for grid-connected power smoothing in this cycle and the single-sided state-of-charge change allowance available for peak shaving and valley filling in this cycle are converted into the power smoothing suppression factor, the allowed state interval for peak shaving and valley filling charging direction, and the allowed state interval for peak shaving and valley filling discharging direction of the power smoothing command in the current control cycle; wherein, the power smoothing suppression factor of the power smoothing command in the current control cycle is a continuous suppression rule based on the remaining margin, used for the amplitude convergence of the power smoothing command; the allowed state interval for peak shaving and valley filling charging direction and the allowed state interval for peak shaving and valley filling discharging direction are directional constraint rules based on interval determination, used for the permissibility determination of the peak shaving and valley filling command.

[0036] Specifically, within the operating cycle, the energy storage system has already determined the available operating boundary through step one, and then further divided the state change space within this boundary into power smoothing behavior limits through step two. Quota for peak shaving and valley filling This step, based on this, transforms the quantitative result of "quota" into constraint rules that can be directly used when generating energy storage power commands. This allows subsequent control to determine whether the command is allowed and the allowable intensity range based on the current state of charge in each control cycle, thereby achieving stable coordination of power smoothing and peak shaving at the engineering level.

[0037] This transformation approach originates from the "state-constrained control" and "soft boundary constraint" methods in classical control theory. Traditional state-constrained control typically employs hard thresholds, directly prohibiting control actions when the system state reaches a boundary. However, in photovoltaic-storage grid-connected scenarios, this hard switching can easily lead to sudden changes in power commands, resulting in grid-connected power fluctuations. This step, based on state constraints, introduces a continuous suppression mechanism based on "residual state margin," transforming hard constraints into continuously adjustable soft constraints, allowing the power smoothing command to gradually converge as it approaches the state boundary. The derivation of this method is based on the fact that the variable range of the energy storage state of charge within the operating cycle has been clearly defined. Therefore, the current state The remaining margin from the boundary of this range can serve as a direct indicator of "the degree to which smooth control can continue to be implemented".

[0038] In practice, the controller reads the current state of charge from the battery management system in each control cycle. and the reference state saved at the start of the running cycle. A comparison is made based on the power smoothing behavior limit given in step two. Constructing the core state range that allows for power smoothing Then, the minimum residual margin from the current state to the upper and lower boundaries of the interval is calculated, and this margin is scaled according to a preset parameter. Normalization is performed to obtain the suppression factor for the power smoothing command. This suppression factor is derived from a piecewise linear function in mathematics and incorporates saturation operators commonly used in control engineering to ensure that the result always falls within the range of... arrive Between them, its expression is:

[0039] in, This represents the power smoothing suppression factor for the power smoothing command within the current control cycle. The state of charge read in the current control cycle; The reference state of charge at the start of the operating cycle; The power smoothing behavior limit is the output of step two; The margin scale parameter configured for the control system is set by engineers during the commissioning phase, specifying the transition width from "fully permissive" to "fully suppressed". In this formula, the numerator represents the remaining margin from the current state to the nearest boundary, and the denominator maps the margin to a dimensionless scale; both have consistent dimensions, and the saturation operator ensures the result does not exceed a reasonable range. When... Located in the middle of the interval and with a remaining margin greater than hour, Smoothing commands are not suppressed; when Approaching the interval boundary and the remaining margin is close to hour, Continuous approach The intensity of the smoothing instruction naturally converges.

[0040] In constructing the constraints for peak shaving and valley filling behavior, this step directly utilizes the peak shaving and valley filling behavior quota obtained in step two. In conjunction with the core region already occupied by power smoothing, an outer state region for peak shaving and valley filling is constructed. This construction follows the unidirectional nature of energy transfer, meaning that peak shaving and valley filling typically progresses continuously in one direction within an operating cycle, with its usable state region closely adjacent to the outer edge of the power smoothing region. Based on this, the usable state regions for peak shaving and valley filling in the charging and discharging directions are defined as follows:

[0041] in, This indicates the allowed state range for peak-shaving and valley-filling charging directions. This indicates the permissible state range for peak-shaving and valley-filling discharge directions; , and All of these are quantities that have been determined in the previous steps. The definition of this interval comes directly from the linear superposition relationship of interval arithmetic. The left and right endpoints are both obtained by combining quantities of the same kind. Logically, the allocatable outer limit is first determined in step two, and then mapped to a clear interval range in this step.

[0042] When peak shaving and valley filling charging is required, a corresponding charging command is only allowed to be generated if the current state of charge falls within the state range that is allowed to be occupied in the peak shaving and valley filling charging direction; when peak shaving and valley filling discharging is required, a corresponding discharging command is only allowed to be generated if the current state of charge falls within the state range that is allowed to be occupied in the peak shaving and valley filling discharging direction.

[0043] As a preferred embodiment, the application process of this rule can be fully demonstrated by combining actual parameters within a running cycle. For example, the initial reference state of the running cycle is... Step 2 Output power smoothing behavior limit Peak shaving and valley filling behavior quota Control system configuration parameters are taken The core region for power smoothing is then... When a certain control cycle reads... At that time, the remaining margins from the current state to the upper and lower boundaries are respectively and The minimum margin is Substituting into the formula for calculating the inhibition factor, we get The smoothing instruction maintains the original amplitude; when reading... At that time, the minimum residual margin is approximately Substituting into The smoothing instruction intensity is significantly compressed. Meanwhile, the outer interval for peak shaving and valley filling is calculated as follows: , In subsequent steps, when generating peak shaving and valley filling related power commands, it is only necessary to determine the current... Whether or not the data falls within the corresponding range determines whether further execution is allowed.

[0044] As can be seen, through the above processing, the behavioral limit given in step two is completely transformed into two types of directly executable engineering constraint rules: one is a continuous suppression rule based on residual margin, used for amplitude convergence of power smoothing commands; the other is a directional constraint rule based on interval determination, used for permissibility judgment of peak shaving and valley filling commands. The two work together to ensure that the subsequent energy storage power command generation process can simultaneously satisfy the state occupancy constraints of smoothing and peak shaving / valley filling in each control cycle, thereby guaranteeing the stability and coordination of the photovoltaic-storage system during grid-connected operation.

[0045] S4. In each control cycle, the original adjustment requirements are confirmed based on the current grid-connected power deviation. At the same time, the continuous suppression rule and / or the directional constraint rule are applied to generate and execute the final energy storage charging and discharging power command, taking into account the current operating stage and energy storage state of charge.

[0046] Specifically, during the operating cycle, the energy storage system has already formed two types of directly determinable constraint rules through the preceding steps: one type is the power smoothing suppression factor that varies with the state of charge. Another type is peak shaving and valley filling, which corresponds to the allowable state ranges in both the charging and discharging directions. and This step, based on this, completes the generation and execution of energy storage charging and discharging power commands. Its core idea comes from the "proportional regulation based on power deviation" method widely used in power system control, and introduces state constraints and suppression factors to enable this proportional regulation to have state safety and behavioral division of labor capabilities in the photovoltaic-storage grid-connected scenario.

[0047] Within each control cycle, the energy management system first reads the current grid-connected power from the grid-connected power measurement device. Simultaneously, the target grid-connected power reference value is read from the operation strategy configuration. The difference between the two reflects the current grid-connected power deviation that the system needs to compensate for through energy storage. Its calculation form is the current grid-connected power deviation. This relationship is directly derived from the classic deviation definition in primary frequency regulation and power point tracking control of power systems. Its physical meaning is: when the grid-connected power is lower than the target value, energy storage needs to discharge to compensate; when the grid-connected power is higher than the target value, energy storage needs to absorb power to charge. Current grid-connected power deviation. The dimensions are consistent with power, serving as the initial adjustment requirements for subsequent command generation. Based on the time period identifier in the operating strategy configuration, the controller assigns the current control cycle to either the peak shaving and valley filling execution phase or the power smoothing phase. During the peak shaving and valley filling execution phase, the directional state interval rules given in step three are used preferentially to generate commands; during the power smoothing phase, the suppression factor rules given in step three are used to generate commands. This execution order remains consistent across each control cycle, ensuring that the power command generation path at any given moment is unique.

[0048] Furthermore, regarding power smoothing behavior, this step will use the suppression factor constructed in step three. The proportional control relationship is directly embedded to form the final executable energy storage power command. The theoretical basis of this approach is the concept of "control gain modulation" in proportional control, which achieves continuous adjustment of control strength by changing the proportional coefficient. In this application, the fixed proportional coefficient is replaced with a state-varying coefficient. This causes the control intensity to automatically weaken as it approaches the state boundary, and the calculation relationship is as follows:

[0049] in, This indicates the energy storage charging and discharging power command generated within the current control cycle; The power smoothing suppression factor obtained in step three has a value determined by the current state of charge. Reference status of the running cycle Power smoothing behavior limit and configuration parameters Joint decision; This represents the current grid-connected power deviation, which is the original adjustment demand obtained based on the grid-connected power deviation. Because... It is a dimensionless quantity. and Maintaining the same physical dimensions satisfies the requirement of dimensional consistency. The derivation logic of this relationship is: when When it is located within the core region of power smoothing and has a large remaining margin near Energy storage operates smoothly according to original demand; when When approaching the interval boundary, Continuous approach The energy storage power command is gradually compressed to avoid out-of-bounds states.

[0050] Furthermore, regarding the peak shaving and valley filling execution phase, the controller first determines the current grid-connected power deviation based on... The sign determines the current energy transfer direction, and based on this, the corresponding allowable range given in step three is selected: when the current grid-connected power deviation... The charging direction is determined and the allowed state range for peak shaving and valley filling charging is selected. When the current grid-connected power deviation The discharge direction is determined and the allowed state interval for peak-shaving and valley-filling discharge is selected. When the current grid-connected power deviation The command directly generates the energy storage charging and discharging power command within the current control cycle. .

[0051] Then compare the current state of charge. Does it fall within the selected interval: When When the selected interval is reached, the energy storage charging and discharging power command generated in the current control cycle is executed. And issue and execute; when If it does not fall within the selected interval, let The instructions are then issued and executed according to the power smoothing path, ensuring that the generated instructions always have a unique result and are continuously constrained by the rules in step three. Through this interval-based determination method, peak shaving and valley filling are always confined to the reserved outer state interval, without encroaching on the core adjustment space of power smoothing.

[0052] As a preferred embodiment, for example, within a certain control cycle, the calculation is obtained. When the time period is identified as a power smoothing phase, the controller presses... Generate and issue instructions; when the time period is marked as the peak shaving and valley filling execution phase and When, the controller selects And judge ,like fall into Then let If the order is issued and implemented, Not fallen Then let Issuance and implementation; the time period was marked as the peak shaving and valley filling implementation phase and When, the controller selects And determine the generation in the same way Through the above process, the relationship between the instruction generation path and the interval selection within the control cycle is clear and consistent.

[0053] This invention also provides a coordinated system for power smoothing and peak shaving / valley filling in a photovoltaic-storage system, the system comprising: The boundary management module is used to determine the symmetrical available power amplitude and available state of charge operating boundary of the energy storage system at the beginning of each operating cycle, based on the maximum charging power and maximum discharging power of the energy storage system in the current operating cycle. The quota allocation module is used to dynamically generate the single-sided state-of-charge change quota available for grid-connected power smoothing and the single-sided state-of-charge change quota available for peak shaving and valley filling in the current cycle, based on the symmetrical available power amplitude of the energy storage system and the total window width based on the available state-of-charge operation boundary within the state-of-charge available operating boundary. The rule generation module is used to convert the single-sided state-of-charge change (SOC) allowance available for grid-connected power smoothing in the current cycle and the single-sided SOC allowance available for peak shaving and valley filling in the current cycle into a power smoothing suppression factor, a permissible state interval for peak shaving and valley filling charging, and a permissible state interval for peak shaving and valley filling discharging in the current control cycle. The power smoothing suppression factor for the power smoothing command in the current control cycle is a continuous suppression rule based on residual margin, used for amplitude convergence of the power smoothing command. The permissible state intervals for peak shaving and valley filling charging and discharging are directional constraint rules based on interval determination, used for permissibility judgment of peak shaving and valley filling commands. The instruction coordination and execution module is used to confirm the original adjustment requirements based on the current grid-connected power deviation in each control cycle, and at the same time, combine the current operating stage and the energy storage state of charge, apply the continuous suppression rule and / or the directional constraint rule, generate the final energy storage charging and discharging power instruction and execute it.

[0054] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0055] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of apparatuses or units may be electrical, mechanical, or other forms.

[0056] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0057] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations 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 coordinated method for power smoothing and peak shaving / valley filling in a photovoltaic-storage system, characterized in that, The method includes: S1. At the beginning of each operating cycle, based on the maximum charging power and maximum discharging power of the energy storage system, determine the symmetrical available power amplitude and the available operating boundary of the state of charge of the energy storage system in the current operating cycle. S2. Within the available operating boundary of the state of charge, based on the symmetrical available power amplitude of the energy storage system and the total window width based on the available operating boundary of the state of charge, dynamically generate the single-sided state of charge change quota available for grid-connected power smoothing in this cycle and the single-sided state of charge change quota available for peak shaving and valley filling in this cycle. S3. The single-sided state-of-charge change allowance available for grid-connected power smoothing in this cycle and the single-sided state-of-charge change allowance available for peak shaving and valley filling in this cycle are converted into the power smoothing suppression factor, the allowed state interval for peak shaving and valley filling charging direction, and the allowed state interval for peak shaving and valley filling discharging direction of the power smoothing command in the current control cycle; wherein, the power smoothing suppression factor of the power smoothing command in the current control cycle is a continuous suppression rule based on the remaining margin, used for the amplitude convergence of the power smoothing command; the allowed state interval for peak shaving and valley filling charging direction and the allowed state interval for peak shaving and valley filling discharging direction are directional constraint rules based on interval determination, used for the permissibility determination of the peak shaving and valley filling command; S4. In each control cycle, the original adjustment requirements are confirmed based on the current grid-connected power deviation. At the same time, the continuous suppression rule and / or the directional constraint rule are applied to generate and execute the final energy storage charging and discharging power command, taking into account the current operating stage and energy storage state of charge.

2. The method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 1, characterized in that, The determination of the symmetrical available power amplitude and available state of charge operating boundary of the energy storage system in the current operating cycle is specifically as follows: Obtain the state of charge of the energy storage system at the start of the current operating cycle; Obtain the maximum charging power and maximum discharging power of the energy storage converter of the energy storage system under the current operating conditions, and take the smaller of the two values ​​as the symmetrical available power amplitude used in this operating cycle; Based on the symmetrical available power amplitude used in this operating cycle, the duration of the operating cycle, and the available energy capacity of the energy storage system, the maximum state of charge change amplitude that the energy storage system can achieve under the power limit constraint within the cycle is calculated. Using the state of charge at the start of the operating cycle as the center and the maximum state of charge change amplitude as the unilateral offset, the usable operating boundary of the state of charge is determined.

3. The method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 1, characterized in that, The specific amounts of single-sided state of charge variation that can be used for dynamic generation of grid-connected power smoothing in this cycle and the single-sided state of charge variation that can be used for peak shaving and valley filling in this cycle are as follows: Based on the symmetrical available power amplitude and the rated power amplitude of the energy storage converter, the power regulation capability strength index is determined. Based on the available operating boundary of the state of charge, determine the total window width of the state of charge that can change within this cycle; Combining the power regulation capability strength index, the total window width of the variable state of charge in this cycle, and the pre-configured reference proportional coefficient, the proportional coefficient allocated to grid-connected power smoothing in this cycle is calculated. According to the above, the total state change space corresponding to the available operating boundary of the state of charge is divided into the single-sided state of charge change quota that can be occupied by grid-connected power smoothing in this cycle and the single-sided state of charge change quota that can be occupied by peak shaving and valley filling in this cycle.

4. The method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 3, characterized in that, The scaling factor is implemented through a saturation operator: When the value inside the parentheses of the saturation operator is less than 0, it takes the value 0; when it is greater than 1, it takes the value 1; otherwise, it takes the original value.

5. The method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 1, characterized in that, The conversion steps for the power smoothing suppression factor of the power smoothing command in the current control cycle include: With the state of charge saved at the start of the current operating cycle as the center and the unilateral state of charge change limit that can be occupied by the grid-connected power smoothing in this cycle as the radius, a core state interval that the power smoothing is allowed to be constructed is constructed. In each control cycle, calculate the remaining margin from the current state of charge to the boundary of the core state interval; Based on the remaining margin, the power smoothing suppression factor of the power smoothing command in the current control cycle is obtained by normalizing according to the preset scale parameter; wherein, when the remaining margin is sufficient, the power smoothing suppression factor is close to 1, and the command is not suppressed; when the remaining margin decreases, the power smoothing suppression factor decreases continuously, and the command amplitude is smoothed and compressed.

6. The method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 5, characterized in that, The power smoothing suppression factor is a segmental linear function, and combined with the saturation operator commonly used in control engineering, it ensures that the result is always between 0 and 1.

7. A method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 5, characterized in that, The conversion steps for the allowed state intervals in the peak-shaving and valley-filling charging direction and the allowed state intervals in the peak-shaving and valley-filling discharging direction include: Based on the core state interval and the single-sided state of charge change limit that can be occupied for peak shaving and valley filling in this cycle, state intervals that can be occupied in the charging direction and the discharging direction for peak shaving and valley filling are respectively constructed outside the core state interval.

8. The method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 7, characterized in that, The directional constraint rules are used to determine the permissibility of peak-shaving and valley-filling commands, specifically as follows: When peak shaving and valley filling charging is required, a corresponding charging command is only allowed to be generated if the current state of charge falls within the state range that is allowed to be occupied in the peak shaving and valley filling charging direction; when peak shaving and valley filling discharging is required, a corresponding discharging command is only allowed to be generated if the current state of charge falls within the state range that is allowed to be occupied in the peak shaving and valley filling discharging direction.

9. A method for coordinating power smoothing and peak shaving / valley filling in a photovoltaic-storage system according to claim 1, characterized in that, The generation of the final energy storage charging and discharging power command specifically involves: During the power smoothing phase, the final energy storage charging and discharging power command is calculated based on the original adjustment demand and the power smoothing suppression factor obtained from the current control cycle; wherein, the original adjustment demand is the current grid-connected power deviation between the current grid-connected power and the target grid-connected power reference value; During the peak shaving and valley filling implementation phase First, determine whether the direction of the current grid-connected power deviation falls within the state range that is allowed to be occupied in the peak-shaving and valley-filling charging direction and the state range that is allowed to be occupied in the peak-shaving and valley-filling discharging direction: If the current grid-connected power deviation is less than 0, it is determined to be the charging direction and the state interval allowed to be occupied by the peak shaving and valley filling charging direction is selected. If the current grid-connected power deviation is greater than 0, it is determined to be the discharge direction and the state interval allowed to be occupied by the peak-shaving and valley-filling discharge direction is selected. If the current grid-connected power deviation is equal to 0, then the energy storage charging and discharging power command generated in the current control cycle is directly set as the current grid-connected power deviation. Then compare whether the current state of charge falls within the selected state range: If the current state of charge falls into the corresponding selected state interval, the energy storage charging and discharging power command generated in the current control cycle is set as the current grid-connected power deviation and is issued for execution; If the current state of charge does not fall into the corresponding selected state interval, the energy storage charging and discharging power command generated in the current control cycle is made to be the product of the current grid-connected power deviation and the power smoothing suppression factor, and is issued and executed according to the power smoothing path.

10. A coordinated system for power smoothing and peak shaving / valley filling in a photovoltaic-storage system, characterized in that, The system includes: The boundary management module is used to determine the symmetrical available power amplitude and available state of charge operating boundary of the energy storage system at the beginning of each operating cycle, based on the maximum charging power and maximum discharging power of the energy storage system in the current operating cycle. The quota allocation module is used to dynamically generate the single-sided state-of-charge change quota available for grid-connected power smoothing and the single-sided state-of-charge change quota available for peak shaving and valley filling in the current cycle, based on the symmetrical available power amplitude of the energy storage system and the total window width based on the available state-of-charge operation boundary within the state-of-charge available operating boundary. The rule generation module is used to convert the single-sided state-of-charge change (SOC) allowance available for grid-connected power smoothing in the current cycle and the single-sided SOC allowance available for peak shaving and valley filling in the current cycle into a power smoothing suppression factor, a permissible state interval for peak shaving and valley filling charging, and a permissible state interval for peak shaving and valley filling discharging in the current control cycle. The power smoothing suppression factor for the power smoothing command in the current control cycle is a continuous suppression rule based on residual margin, used for amplitude convergence of the power smoothing command. The permissible state intervals for peak shaving and valley filling charging and discharging are directional constraint rules based on interval determination, used for permissibility judgment of peak shaving and valley filling commands. The instruction coordination and execution module is used to confirm the original adjustment requirements based on the current grid-connected power deviation in each control cycle, and at the same time, combine the current operating stage and the energy storage state of charge, apply the continuous suppression rule and / or the directional constraint rule, generate the final energy storage charging and discharging power instruction and execute it.

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