Distributed photovoltaic and energy storage coordinated power distribution network voltage fluctuation suppression method and system

Abstract

The invention discloses a distributed photovoltaic and energy storage cooperative power distribution network voltage fluctuation suppression method and system, and relates to the technical field of voltage fluctuation suppression, and the method comprises the following steps: building an inter-node disturbance propagation accessibility matrix based on the real-time operation data of a power distribution network, and recognizing a voltage disturbance path set; constructing a disturbance irreversible structure chart based on the voltage disturbance path set, and identifying a one-way amplification chain; according to historical disturbance data of a unidirectional amplification chain source node, calculating a disturbance excitation probability and generating a disturbance active propagation domain; constructing an energy storage intervention buffer area in the disturbance active propagation domain; in the energy storage intervention buffer area, the reverse blocking capability of energy storage is evaluated by simulating disturbance propagation, and a collaborative strategy activation condition is generated. Through disturbance path simulation evaluation, energy storage redundancy configuration and power consumption are reduced, and the suppression efficiency and adaptability of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage fluctuation suppression, and more specifically, to a method and system for suppressing voltage fluctuations in a distribution network coordinated by distributed photovoltaics and energy storage. Background Art

[0002] As the proportion of distributed photovoltaic power generation in distribution networks continues to increase, voltage disturbances in grid operation exhibit complex spatiotemporal propagation characteristics. PV output fluctuations are not only affected by environmental factors, but the resulting voltage disturbances also propagate along the distribution network topology, exhibiting a distinct path structure irreversibility. Disturbances generated by certain nodes can only propagate downstream in a specific direction and are difficult to offset in the opposite direction along the same path. Once a disturbance is amplified on a particular link, traditional single-point regulation or simple distributed control methods are unable to effectively pull back or suppress voltage fluctuations, and may even lead to cumulative and exacerbated disturbances.

[0003] While existing technologies, such as multi-level coordination, distributed scheduling, or regulation methods based on frequency stability analysis, can mitigate voltage fluctuations to a certain extent, none of them establishes a detailed model for the irreversible path structure characteristics of voltage disturbance propagation, nor does it design dynamic control strategies based on chain fragility and node regulation capabilities. Therefore, in scenarios with a high proportion of PV access, traditional regulation strategies struggle to achieve high-precision suppression and rapid response, and voltage fluctuations remain a prominent issue.

[0004] The above-mentioned disclosed technical solutions have at least the following technical problems: the existing collaborative regulation mechanism does not explicitly model the irreversible structural characteristics of the path of voltage disturbance propagation, resulting in the inability to effectively converge the regulation process and even exacerbating the cumulative effect of the disturbance in the network.

[0005] In view of the above problems, the present invention proposes a solution. Summary of the Invention

[0006] To overcome the above-mentioned shortcomings of the prior art, embodiments of the present invention provide a method and system for suppressing voltage fluctuations in a distribution network by coordinating distributed photovoltaics and energy storage. By identifying the voltage disturbance path and the unidirectional amplification chain, an active disturbance propagation domain is generated, and a minimum closed control chain and energy storage buffer zone are reversely constructed within the domain. The reverse blocking capability of the energy storage is evaluated and the control strategy is corrected in real time, thereby achieving coordinated regulation of photovoltaics and energy storage, and solving the problems of regulation delay and incomplete suppression caused by the irreversibility of voltage disturbances in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions: On the one hand, the method for suppressing distribution network voltage fluctuations by coordinating distributed photovoltaics and energy storage includes the following steps: based on the real-time operation data of the distribution network, constructing a disturbance propagation reachability matrix between nodes and identifying a set of voltage disturbance paths; constructing a disturbance irreversible structure diagram based on the set of voltage disturbance paths and identifying a one-way amplification chain; calculating the disturbance excitation probability and generating a disturbance active propagation domain based on the historical disturbance data of the source node of the one-way amplification chain; constructing an energy storage intervention buffer zone within the disturbance active propagation domain; and within the energy storage intervention buffer zone, evaluating the reverse blocking capability of the energy storage by simulating disturbance propagation to generate activation conditions for the collaborative strategy.

[0008] In a preferred embodiment, the method is to construct an inter-node disturbance propagation reachability matrix based on the real-time operation data of the distribution network and identify a set of voltage disturbance paths. The specific method is as follows: obtain the real-time operation data of the distribution network and generate a disturbance-response sample set through distributed active detection; calculate the equivalent path impedance based on the topological structure data and construct a model prior sensitivity matrix; perform regularized time series regression on the disturbance-response sample set to generate a data-driven sensitivity matrix; perform topology-aware fusion of the model prior sensitivity matrix and the data-driven sensitivity matrix to form a directional disturbance propagation reachability matrix; perform threshold clipping on the reachability matrix and search for all path sets that meet the directional consistency constraint; eliminate paths in the path set that contain self-loops or direction reversal links to obtain the final voltage disturbance path set.

[0009] In a preferred embodiment, the model prior sensitivity matrix and the data-driven sensitivity matrix are topologically fused, specifically: determining the node connectivity, electrical distance and disturbance propagation direction tendency based on the distribution network topology structure; evaluating the credibility weights of the model prior sensitivity matrix and the data-driven sensitivity matrix respectively, and extracting the temporal causal information between the nodes; jointly optimizing and solving the two types of sensitivity matrices with the credibility weights, temporal causal information and topological adjacency information as constraints to obtain a fusion matrix; performing directionality projection and screening on the fusion matrix according to the electrical distance, disturbance propagation direction tendency and directional threshold, and outputting a directional disturbance propagation reachability matrix.

[0010] In a preferred embodiment, the method of constructing a disturbance irreversible structure diagram based on a voltage disturbance path set and identifying a unidirectional amplification chain is as follows: based on the size relationship between the element value of the topology-aware accessibility matrix and the reverse element, the directional index of each edge in the voltage disturbance path set is calculated, and the unidirectional disturbance edge is identified according to the preset judgment condition; by removing the non-unidirectional disturbance edge in the voltage disturbance path set, an irreversible structure diagram reflecting the unidirectional propagation characteristics of the disturbance is constructed; for each directed path of the irreversible structure diagram, the forward path amplification amount and the reverse amplification amount are calculated respectively, and the quantization ratio of irreversibility is obtained; the unidirectional amplification chain is screened according to the quantization ratio, and the path vulnerability index is combined for sorting, and the unidirectional amplification chain set is output, and the chain head driving source node and the chain tail diffusion node of each chain are determined.

[0011] In a preferred embodiment, the calculation of the disturbance excitation probability and the generation of the disturbance active propagation domain based on the historical disturbance data of the source node of the unidirectional amplification chain is specifically as follows: Acquire second data of the chain-head driving source node in the unidirectional amplification chain, wherein the second data includes: a short-term output fluctuation rate index of distributed photovoltaics, a photovoltaic output standard deviation, and a topological sensitivity position measurement of the driving node in the irreversible structure diagram; calculate the single-point excitation probability of the chain-head driving source node based on the second data, and couple the single-point excitation probability with the structural amplification amount of the chain to generate the overall disturbance excitation probability of the chain; screen the chains whose overall disturbance excitation probability exceeds a preset activation threshold and classify them into the disturbance active propagation domain.

[0012] In a preferred embodiment, the construction of the energy storage intervention buffer zone includes the step of generating a minimum closed inverse control chain, specifically: using the tail node of the unidirectional amplification chain in the active propagation domain of the disturbance as the control anchor point, screening a candidate set of energy storage units that meet the electrical distance according to preset performance constraints; arranging the candidate energy storage units in the order of chain segments along the unidirectional amplification chain from the tail to the head to form a reverse control relay sequence; with covering all amplification segments of the chain as a necessary constraint and minimizing the total amount of control resources as the optimization goal, generating a minimum closed inverse control chain and a corresponding segment-energy storage mapping list.

[0013] In a preferred embodiment, the construction of the energy storage intervention buffer is specifically as follows: based on the minimum closed inverse control chain and its segment-energy storage mapping list, the necessary control chain coverage thresholds including structural coverage, dynamic response coverage and energy coverage are set; the actual coverage index is compared with the coverage threshold chain by chain to identify the amplification segment that does not meet the standard; from the tail node of the chain toward the upstream direction, the non-compliant segment is expanded in a preset priority order to form an energy storage intervention buffer, and spare energy storage units, droop coefficients, power caps and state retention strategies are pre-set in the buffer, and the buffer configuration list and activation priority table are output.

[0014] In a preferred embodiment, within the energy storage intervention buffer, the reverse blocking capability of the energy storage is evaluated by simulating disturbance propagation to generate the activation conditions of the collaborative strategy. Specifically, a disturbance propagation simulation model is constructed based on the buffer configuration list and activation priority, including a node voltage dynamic equation, an energy storage power-voltage coupling model, and a reverse relay control logic; an equivalent photovoltaic output fluctuation signal is sequentially injected along the disturbance active propagation domain chain, and the reverse control response of the energy storage in the buffer is triggered in real time. The reverse blocking capability index obtained by weighted normalization of the voltage recovery rate, response time margin, and energy utilization efficiency is calculated and compared with the preset criteria to generate the activation conditions of the collaborative strategy.

[0015] On the other hand, the distribution network voltage fluctuation suppression system with coordinated distributed photovoltaic and energy storage includes the following modules: disturbance reachability modeling module: used to construct the disturbance propagation reachability matrix between nodes based on the real-time operation data of the distribution network, and identify the voltage disturbance path set; irreversible disturbance structure identification module: used to construct the disturbance irreversible structure diagram based on the voltage disturbance path set, and identify the one-way amplification chain; active propagation domain generation module: used to calculate the disturbance excitation probability and generate the disturbance active propagation domain based on the historical disturbance data of the source node of the one-way amplification chain; buffer configuration module: used to construct the energy storage intervention buffer zone within the disturbance active propagation domain; energy storage reverse blocking capability evaluation module: used to evaluate the reverse blocking capability of energy storage by simulating disturbance propagation within the energy storage intervention buffer zone, and generate the activation conditions of the collaborative strategy.

[0016] The technical effects and advantages of the distributed photovoltaic and energy storage coordinated distribution network voltage fluctuation suppression method and system of the present invention are as follows: 1. This invention combines a physical prior model with a data-driven sensitivity matrix through "topology-aware fusion" to form a directional disturbance propagation reachability matrix. Combined with threshold clipping and depth-first traversal, it accurately eliminates weak propagation paths and reverse loops, ultimately obtaining a true set of voltage disturbance paths. Furthermore, by using unidirectional disturbance edges and irreversibility ratio determination, unidirectional amplification chains and their driving source nodes can be quickly identified, enabling high-resolution tracing and probabilistic prediction of chain-like voltage fluctuations, significantly improving the accuracy of grid operating status perception and early warning of disturbance risks.

[0017] 2. Based on the identification of the active propagation domain of disturbances, this invention reversely generates a minimum closed inverse control chain according to the chain topology. It also introduces triple thresholds of structural coverage, dynamic response coverage, and energy coverage to construct an energy storage intervention buffer zone, enabling the energy storage to provide continuous, rapid, and segmented reverse voltage regulation during the disturbance growth phase. By simulating the disturbance path to evaluate the reverse blocking capability index and combining it with a dynamic disturbance structure evolution feedback mechanism, the control strategy can be modified and prioritized in real time. This ensures suppression effectiveness while reducing energy storage redundancy and power consumption, thereby improving the system's suppression efficiency and adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the flow of the method for suppressing voltage fluctuations in a distribution network by coordinating distributed photovoltaic and energy storage systems according to the present invention; Figure 2 This is a schematic diagram of the structure of the distributed photovoltaic and energy storage coordinated distribution network voltage fluctuation suppression system of the present invention. DETAILED DESCRIPTION

[0019] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1, Figure 1 The present invention provides a method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration, comprising the following steps: S1, based on the real-time operation data of the distribution network, constructs the inter-node disturbance propagation reachability matrix and identifies the set of voltage disturbance paths; In this embodiment, the real-time operation data includes topological structure data of the distribution network and voltage sensitivity indexes between nodes measured based on a disturbance injection method; Based on the real-time operation data of the distribution network, the inter-node disturbance propagation reachability matrix is ​​constructed to identify the voltage disturbance path set, specifically: Acquire real-time operation data of the distribution network and generate disturbance-response sample sets through distributed active detection; Calculate the equivalent path impedance based on topological structure data and construct the model prior sensitivity matrix; Perform regularized time series regression on the disturbance-response sample set to generate a data-driven sensitivity matrix; The model prior sensitivity matrix and the data-driven sensitivity matrix are topologically fused to form a directional disturbance propagation reachability matrix. Threshold pruning is performed on the reachability matrix to eliminate weak propagation paths with weights below the preset threshold, and a depth-first traversal is used to search the matrix for all paths that meet the directional consistency constraint. Eliminate the paths containing self-loops or direction reversal links in the path set to obtain the final voltage disturbance path set.

[0021] The topology-aware fusion of the model prior sensitivity matrix and the data-driven sensitivity matrix is ​​specifically as follows: Based on the topological structure data of the distribution network, the connectivity relationship between nodes and the electrical distance of the lines are determined to form topological adjacency information that reflects the structural connectivity and transmission attenuation characteristics. The disturbance propagation direction tendency between nodes is determined based on the line impedance phase angle. The credibility weights of the model prior sensitivity matrix and the data-driven sensitivity matrix between each node pair are evaluated respectively, and the temporal causal information between nodes is obtained through historical operation data to reflect the temporal order of disturbance propagation. During the fusion process, credibility weights, temporal causal information, and topological adjacency information are used as constraints. The model prior sensitivity matrix and the data-driven sensitivity matrix are jointly optimized and solved. The resulting fusion matrix ensures that the fusion result is numerically close to both the data observation and the physical prior, and structurally complies with the electrical topology reachability constraints. The fusion matrix is ​​projected and screened according to the line electrical distance, disturbance propagation direction tendency and the preset directional threshold. The edges that do not meet the unidirectional propagation characteristics in terms of directionality are eliminated, and the retained edge weights are normalized to obtain the directional disturbance propagation reachability matrix.

[0022] The specific calculation formula for topology perception fusion is:

[0023]

[0024] in, is the topology-aware fusion weight of node j with node i, is the sensitivity of node j power disturbance to node i voltage amplitude, The impedance between nodes The directional function is determined by the phase angle sign. If the disturbance propagation direction is consistent with the power flow direction, the value is 1, otherwise it is 0. Line-based The propagation attenuation factor, is the attenuation coefficient, is the voltage regulation capability loss factor of node i (the weaker the regulation capability, the larger the value), is the voltage change of node i before and after the disturbance, is the reactive disturbance injected at node j.

[0025] In this embodiment, the distributed active detection is specifically as follows: the selected photovoltaic inverter / energy storage inverter applies small, orderly injection disturbances (±ΔP, ±ΔQ) in different short time periods, and simultaneously records the multi-point time-series voltage responses to form a disturbance-response test data set.

[0026] S2, based on the voltage perturbation path set, constructs a perturbation irreversible structure diagram and identifies the unidirectional amplification chain, specifically: For each directed edge (u, v) in the voltage disturbance path set, the directionality coefficient is calculated based on the relationship between the element value of the topology-aware reachability matrix and the size of the reverse element, and the edge with a direction greater than the preset threshold is determined as a unidirectional disturbance edge; Based on the voltage perturbation path set, the edges that do not meet the directionality judgment are removed to obtain a directed subgraph containing only unidirectional perturbation edges as the perturbation irreversible structure graph; Based on the perturbed irreversible structure graph, the directed path amplification and reverse amplification are calculated, and the irreversibility ratio is obtained; Paths that meet the conditions are screened as candidate one-way amplification chains, and the final one-way amplification chain set is output by sorting the chain fragility, and the chain head driving source node and chain tail diffusion node of each chain are determined.

[0027] In this embodiment, the path that meets the conditions is specifically: A path in which the amplification amount is greater than a preset amplification amount threshold and the irreversibility ratio is greater than a preset ratio threshold.

[0028] The specific calculation formula of the directional index is:

[0029] The specific calculation formulas for the amplification amount and the reverse amplification amount are as follows:

[0030]

[0031] The specific calculation formula of the irreversibility ratio is:

[0032] in, is the directivity coefficient, is the element value of the topology-aware reachability matrix, is the reverse element value, is a very small constant to avoid the denominator being 0, To increase the amount, is the topology-aware fusion weight, To reverse the amount of amplification, is the irreversibility ratio.

[0033] S3, based on the historical disturbance data of the source node of the one-way amplification chain, calculates the disturbance excitation probability and generates the disturbance active propagation domain; The historical disturbance data includes the fluctuation characteristics of distributed photovoltaic output, topological sensitivity position, and voltage regulation capability deficiency index; In this embodiment, the disturbance excitation probability is calculated and the disturbance active propagation domain is generated based on the historical disturbance data of the source node of the unidirectional amplification chain, specifically: Get a one-way amplification chain Historical disturbance data at the chain head driving source node, the second data includes: the short-term output fluctuation rate index of distributed photovoltaic , photovoltaic output standard deviation and the topological sensitivity position metric of the driving node in the irreversible structure graph ; According to the historical disturbance data, the single-point excitation probability of the chain head driving source node is calculated, and the single-point excitation probability is coupled with the structural amplification of the chain to calculate the overall disturbance excitation probability of the chain; All chains that meet the preset activation threshold constraint are classified into the disturbance active propagation domain.

[0034] The activation threshold is adaptively determined based on historical samples.

[0035] In this embodiment, the single point excitation probability is specifically:

[0036] The overall disturbance excitation probability is specifically calculated as follows:

[0037] in, is the single point excitation probability, 、 、 is the weight coefficient (obtained based on historical sample training), is the short-term output fluctuation rate indicator of distributed photovoltaics, is the standard deviation of photovoltaic output, is the topological sensitivity position measurement of the driving node in the irreversible structure graph, is the mapping function that maps the linear combination to the probability value, is the overall perturbation excitation probability, To increase the amount, 、 is the normalization function used for scale transformation.

[0038] S4, constructing an energy storage intervention buffer zone within the active propagation domain of disturbance; In this embodiment, the construction of the energy storage intervention buffer zone includes the steps of generating a minimum closed inverse control chain, specifically: In the active propagation domain of disturbances, the tail node of each unidirectional amplification chain is used as the anchor point. Based on the constraints of reverse voltage regulation accessibility, controllable margin, communication delay, and state availability, a candidate set of energy storage units within the permitted electrical distance range is screened. Based on the candidate set of energy storage units, a reverse control relay sequence is established from the end of the chain to the beginning of the chain in the order of the chain segments, so that adjacent relay nodes have continuous response capabilities within the time window and meet the local voltage pullback requirements; Taking the reverse controllability of covering all amplification segments of the chain as a necessary constraint and the sum of the number of energy storage and communication links as the optimization goal, the minimum energy storage set that can close the chain is determined, and the corresponding minimum closed inverse control chain is generated. The chain segment-energy storage mapping list, the response time window of each relay node, and the preset voltage-reactive / active power adjustment parameters are simultaneously output, which are used as input for subsequent path suppression coverage evaluation and buffer zone construction.

[0039] The screening of the candidate set of energy storage units within the permitted electrical distance range is specifically as follows: Taking the tail node of the unidirectional amplification chain as the center, calculate the electrical distance from the tail node to other nodes according to the distribution network topology and line impedance, and eliminate energy storage units that exceed the preset maximum allowable distance; The reverse voltage regulation sensitivity of the remaining energy storage units at the chain tail node is calculated respectively, and the energy storage units with a sensitivity lower than the reverse adjustable lower limit are eliminated to ensure that they have the ability to effectively pull back the chain tail voltage; Evaluate the controllable margin of each energy storage unit, that is, the proportion of active / reactive regulation capacity that can be immediately dispatched under the current operating state to its rated capacity, and eliminate units that fall below the minimum margin threshold; Combining the distribution network communication topology and delay statistics, determine whether the one-way delay of the control command of each energy storage unit is within the allowable range of the chain segment disturbance growth time constant, and eliminate the exceeding units; Retrieve the status availability labels of energy storage units, eliminate units in maintenance, off-grid, or power-limited mode, retain energy storage units that meet all constraints, form a candidate set of energy storage units for the tail node of the chain, and attach a reverse regulation priority label to each candidate unit.

[0040] The construction of the energy storage intervention buffer zone is specifically as follows: Based on the minimum closed inverse control chain and its segment-energy storage mapping list, necessary control chain coverage thresholds are set, including structural coverage, dynamic response coverage, and energy coverage. The structural coverage is used to determine whether each amplification segment of the chain is reversely controlled by at least one energy storage relay node. The dynamic response coverage is used to determine whether each relay node can complete continuous relay within the specified time window. The energy coverage is used to determine whether the energy storage power and available power meet the suppression requirements during the expected disturbance duration. The actual coverage index is compared with the coverage threshold chain by chain, and the amplification sections that do not meet the standards are expanded from the end of the chain to the upstream according to priority to form an energy storage intervention buffer. Spare energy storage units, droop coefficients, power caps and state retention strategies are pre-set in the buffer, and a buffer configuration list and activation priority table are output.

[0041] S5: Within the energy storage intervention buffer zone, the reverse blocking capability of energy storage is evaluated by simulating disturbance propagation, and the activation conditions of the collaborative strategy are generated. Specifically, The buffer configuration list and activation priority table of the energy storage intervention buffer zone are used as simulation inputs to build a multi-timescale disturbance propagation simulation platform that includes node voltage dynamic equations, energy storage power-voltage coupling model, and reverse relay control logic. According to the chain topology of the active disturbance propagation domain, equivalent photovoltaic output fluctuation signals are injected from the beginning to the end of the chain. In the simulation, the reverse control response of the energy storage in the buffer zone is triggered in real time, and the voltage pull-back time, disturbance attenuation coefficient, and power consumption curve of the chain segment are recorded. Calculate the reverse blocking capability index of each energy storage relay segment. The reverse blocking capability index is obtained by weighted normalization of the segment voltage recovery rate, response time margin, and energy utilization efficiency, and compare it with the set blocking capability criterion on a chain-by-chain basis. Based on the comparison results, the activation conditions of the collaborative strategy are generated. The activation conditions include the triggering disturbance power threshold, the lower limit of the segment blocking capacity and the threshold of the remaining energy storage energy ratio. The activation conditions are used as direct input to the subsequent online control system to determine whether to start the energy storage collaborative reverse blocking strategy during actual network operation.

[0042] In this embodiment, the reverse blocking capability index is specifically calculated as follows:

[0043]

[0044]

[0045]

[0046]

[0047] in, is the reverse blocking capability index, is the voltage recovery rate, is the response time margin, is the energy utilization efficiency, 、 、 are weight factors (obtained based on historical data), is the maximum voltage drop of the tail node under uncontrolled conditions, is the instantaneous voltage drop value under control conditions, For the evaluation time domain The remnant falls at the end, is the allowed suppression time limit of the chain segment, The time it takes for the voltage at the end of the chain to return to the preset reference threshold. is the voltage drop area difference between the uncontrolled and controlled conditions of the chain segment, is the energy scale conversion factor ( ,in, is the system rated power, is the voltage reference value), For energy storage The actual energy consumed, is the normalization function.

[0048] In this embodiment, the method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration of the present invention further includes the following steps: Construct a dynamic disturbance structure evolution feedback mechanism to correct the collaborative control strategy path in real time, specifically: During actual operation, the voltage fluctuation and propagation trend in the network are monitored, and the reachability matrix and irreversible path structure are updated in real time; If the current regulatory behavior fails to achieve path suppression or a new irreversible path is stimulated, the retrospective correction strategy activates the region, intervention node priority and control chain structure to form a structural dynamic adaptive closed loop.

[0049] The structural evolution feedback mechanism includes the following processing logic: Update the accessibility matrix in real time and perform irreversibility assessment on newly added disturbance paths; Reassign energy storage regulation responsibility nodes for unclosed paths of the control strategy; Update the collaborative priority weight vector for high-frequency activation paths; A regulatory warning sign is output for areas where closed-loop suppression is not formed after the strategy is executed.

[0050] Example 2, the distributed photovoltaic and energy storage coordinated distribution network voltage fluctuation suppression system of the present invention includes the following modules: Disturbance reachability modeling module: used to construct the inter-node disturbance propagation reachability matrix based on the real-time operation data of the distribution network and identify the set of voltage disturbance paths; Irreversible disturbance structure identification module: used to construct a disturbance irreversible structure diagram based on the voltage disturbance path set and identify the unidirectional amplification chain; Active propagation domain generation module: used to calculate the disturbance excitation probability and generate the disturbance active propagation domain based on the historical disturbance data of the source node of the unidirectional amplification chain; Buffer configuration module: used to construct energy storage intervention buffer zone within the active propagation domain of disturbance; Energy storage reverse blocking capability assessment module: used to assess the reverse blocking capability of energy storage within the energy storage intervention buffer zone by simulating disturbance propagation and generating the activation conditions for the collaborative strategy.

[0051] The above formulas are all dimensionless and numerical calculations. The formulas are obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formulas are set by technicians in this field according to actual conditions.

[0052] The above embodiments may be implemented in whole or in part through software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0053] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0054] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0055] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0056] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for suppressing voltage fluctuations in a distribution network using the collaboration of distributed photovoltaics and energy storage, characterized in that: The following steps are involved: Based on the real-time operation data of the distribution network, the inter-node disturbance propagation reachability matrix is ​​constructed to identify the set of voltage disturbance paths; Based on the voltage perturbation path set, a perturbation irreversible structure diagram is constructed to identify the unidirectional amplification chain; According to the historical disturbance data of the source node of the one-way amplification chain, the disturbance excitation probability is calculated and the active propagation domain of the disturbance is generated; Constructing energy storage intervention buffer zones within the active propagation domain of disturbances; Within the energy storage intervention buffer zone, the reverse blocking capability of energy storage is evaluated by simulating disturbance propagation, and the activation conditions of the collaborative strategy are generated.

2. The method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration according to claim 1 is characterized in that: Based on the real-time operation data of the distribution network, the inter-node disturbance propagation reachability matrix is ​​constructed to identify the voltage disturbance path set. The specific method is as follows: Obtain real-time operation data of the distribution network and generate disturbance-response sample sets through distributed active detection; Calculate the equivalent path impedance based on topological structure data and construct the model prior sensitivity matrix; Perform regularized time series regression on the disturbance-response sample set to generate a data-driven sensitivity matrix; The model prior sensitivity matrix and the data-driven sensitivity matrix are topologically fused to form a directional disturbance propagation reachability matrix. Perform threshold pruning on the reachability matrix and search for all paths that meet the direction consistency constraint. Eliminate the paths containing self-loops or direction reversal links in the path set to obtain the final voltage disturbance path set.

3. The method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration according to claim 2, characterized in that: The topology-aware fusion of the model prior sensitivity matrix and the data-driven sensitivity matrix is ​​specifically as follows: Determine node connectivity, electrical distance, and disturbance propagation direction based on the distribution network topology; Evaluate the credibility weights of the model prior sensitivity matrix and the data-driven sensitivity matrix respectively, and extract the temporal causal information between nodes; With the credibility weight, temporal causal information and topological adjacency information as constraints, the two types of sensitivity matrices are jointly optimized and solved to obtain the fusion matrix. According to the electrical distance, disturbance propagation direction tendency and directional threshold, the fusion matrix is ​​directional projected and screened, and the directional disturbance propagation reachability matrix is ​​output.

4. The method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration according to claim 3 is characterized in that: The method of constructing a disturbance irreversible structure diagram based on the voltage disturbance path set and identifying a unidirectional amplification chain is as follows: Based on the relationship between the element values ​​and the reverse elements of the topology-aware reachability matrix, the directional index of each edge in the voltage disturbance path set is calculated, and the unidirectional disturbance edge is identified according to the preset judgment conditions. By removing the non-unidirectional disturbance edges in the voltage disturbance path set, an irreversible structure graph reflecting the unidirectional propagation characteristics of the disturbance is constructed; For each directed path of the irreversible structure graph, the forward path amplification and the reverse path amplification are calculated respectively, and the quantitative ratio of irreversibility is obtained; One-way amplification chains are screened according to the quantitative ratio, sorted according to the path vulnerability index, and a set of one-way amplification chains is output. The head driving source node and the tail diffusion node of each chain are determined.

5. The method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration according to claim 4 is characterized in that: The method of calculating the disturbance excitation probability and generating the disturbance active propagation domain based on the historical disturbance data of the source node of the one-way amplification chain is specifically as follows: Acquire second data of a first driving source node in a unidirectional amplification chain, the second data including: a short-term output fluctuation rate index of distributed photovoltaics, a photovoltaic output standard deviation, and a topological sensitivity position measurement of the driving node in an irreversible structure diagram; Calculate the single-point excitation probability of the chain head driving source node based on the second data, and perform coupling operation on the single-point excitation probability and the structural amplification of the chain to generate the overall perturbation excitation probability of the chain; Chains whose overall disturbance excitation probability exceeds the preset activation threshold are screened and classified into the disturbance active propagation domain.

6. The method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration according to claim 5 is characterized in that: The construction of the energy storage intervention buffer zone includes the steps of generating a minimum closed inverse control chain, specifically: Taking the tail node of the unidirectional amplification chain in the active propagation domain of disturbance as the control anchor point, the candidate set of energy storage units that meet the electrical distance is selected according to the preset performance constraints; Arranging the candidate energy storage units in the order of chain segments from the end of the chain to the beginning of the chain along the unidirectional amplification chain to form a reverse control relay sequence; With covering all amplification segments of the chain as a necessary constraint and minimizing the total amount of control resources as the optimization goal, a minimum closed inverse control chain and the corresponding chain segment-energy storage mapping list are generated.

7. The method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration according to claim 6, characterized in that: The energy storage intervention buffer zone is constructed as follows: Based on the minimum closed inverse control chain and its segment-energy storage mapping list, the necessary control chain coverage thresholds including structural coverage, dynamic response coverage and energy coverage are set; Comparing the actual coverage index with the coverage threshold chain by chain to identify the amplified segments that do not meet the criteria; From the tail node to the upstream, the non-compliant sections are expanded according to the preset priority order to form an energy storage intervention buffer zone. Preset backup energy storage units, droop coefficients, power caps, and state retention strategies in the buffer zone, and output a buffer zone configuration list and activation priority table.

8. The method for suppressing voltage fluctuations in a distribution network using distributed photovoltaic and energy storage collaboration according to claim 7 is characterized in that: In the energy storage intervention buffer zone, the reverse blocking capability of the energy storage is evaluated by simulating disturbance propagation, and the activation conditions of the collaborative strategy are generated, specifically: Based on the buffer configuration list and activation priority, a disturbance propagation simulation model is constructed, which includes node voltage dynamic equations, energy storage power-voltage coupling model, and reverse relay control logic; Equivalent photovoltaic output fluctuation signals are injected sequentially along the active propagation domain chain of disturbances, and the reverse control response of the energy storage in the buffer zone is triggered in real time. The reverse blocking capability index obtained by weighted normalization of voltage recovery rate, response time margin and energy utilization efficiency is calculated and compared with the preset criteria to generate the activation conditions of the collaborative strategy.

9. A system using the method for suppressing voltage fluctuations in a distribution network by coordinating distributed photovoltaic and energy storage as described in any one of claims 1 to 8, characterized in that: Includes the following modules: Disturbance reachability modeling module: used to construct the inter-node disturbance propagation reachability matrix based on the real-time operation data of the distribution network and identify the set of voltage disturbance paths; Irreversible disturbance structure identification module: used to construct a disturbance irreversible structure diagram based on the voltage disturbance path set and identify the unidirectional amplification chain; Active propagation domain generation module: used to calculate the disturbance excitation probability and generate the disturbance active propagation domain based on the historical disturbance data of the source node of the unidirectional amplification chain; Buffer configuration module: used to construct energy storage intervention buffer zone within the active propagation domain of disturbance; Energy storage reverse blocking capability assessment module: used to assess the reverse blocking capability of energy storage within the energy storage intervention buffer zone by simulating disturbance propagation and generating the activation conditions for the collaborative strategy.

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