Reactive power regulation method and device for new energy station
By acquiring data from renewable energy power plants and the power grid, the impact of reactive power regulation on nodes was determined, control areas were divided, stability indicators were constructed, and target reactive power regulation was optimized. This solved the problem of differences in reactive power regulation at renewable energy power plants on node voltage support, and improved the stability and regulation efficiency of the power grid.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CENT CHINA BRANCH OF STATE GRID CORP OF CHINA
- Filing Date
- 2026-04-13
- Publication Date
- 2026-07-10
Smart Images
Figure CN122371364A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of reactive power control technology in power systems, and particularly to a reactive power control method and device for new energy power plants. Background Technology
[0002] As the scale of renewable energy grid connection continues to increase, the reactive power interaction between renewable energy power plants and the grid has an increasingly significant impact on system voltage levels and stability. Especially in scenarios with a high proportion of renewable energy integration, the fluctuating and intermittent nature of renewable energy output can easily cause changes in power flow distribution and local voltage fluctuations, thereby affecting the safe and stable operation of the system. Therefore, it is necessary to rationally determine the reactive power regulation of renewable energy power plants based on the grid operating status and the relationship between reactive power regulation at each node voltage. This can improve the targeting and effectiveness of voltage control, thereby helping to ensure the stable operation of the grid.
[0003] In existing technologies, voltage regulation for voltage issues caused by grid connection of new energy sources typically employs methods such as reactive power compensation devices, inverter reactive power control, and centralized or distributed voltage control. However, existing technologies do not adequately consider the varying support effects of reactive power regulation at different nodes in new energy power plants. This makes it difficult to rationally allocate reactive power regulation resources and accurately determine the target reactive power regulation amount for each new energy power plant based on the voltage status and stability of different nodes, resulting in poor voltage support at key nodes and low overall regulation efficiency. Summary of the Invention
[0004] This invention provides a reactive power regulation method and device for new energy power plants, which solves the defects in the prior art that do not adequately consider the differences in the supporting effect of reactive power regulation on the voltage of different nodes, and make it difficult to rationally allocate reactive power regulation resources and accurately determine the target reactive power regulation amount of each new energy power plant according to the voltage status and stability of different nodes.
[0005] This invention provides a reactive power control method for new energy power plants, comprising: The process involves acquiring operational data from renewable energy power plants and the power grid, including the voltage and power of each node. Based on these data, the impact of reactive power regulation at each renewable energy power plant on the voltage of each node is determined. According to this impact, control zones are divided for each node in the power grid, resulting in control zone divisions corresponding to each renewable energy power plant. Stability indices are constructed for each node based on its voltage, and distance characteristics between the operating state of each node and a reference boundary are determined based on these indices. Based on the control zone divisions, the distance characteristics, and the voltage deviation of each node relative to a preset voltage reference value, a target reactive power regulation amount is determined for each renewable energy power plant, and a reactive power regulation command is generated for the corresponding renewable energy power plant based on the target reactive power regulation amount.
[0006] According to the reactive power regulation method for new energy power plants provided by the present invention, the step of constructing a stability index for each node based on the voltage of each node, and determining the distance representation quantity between the operating state of each node and the reference boundary based on the stability index, includes: constructing a stability index corresponding to each node based on the voltage of each node, mapping the stability index corresponding to each node to a stability index plane to determine the mapping position of each node in the stability index plane; and determining the distance representation quantity between the corresponding node and the reference boundary in the stability index plane based on the mapping position.
[0007] According to the reactive power regulation method for new energy power plants provided by the present invention, the step of constructing a stability index for each node based on the voltage of each node, and determining a distance characterization quantity between the operating state of each node and the reference boundary based on the stability index, further includes: determining a disturbance correction coefficient based on the voltage drop amplitude of each node under the current operating condition, and correcting the reference boundary based on the disturbance correction coefficient.
[0008] According to the reactive power regulation method for new energy power plants provided by the present invention, determining the target reactive power regulation amount for each new energy power plant includes: determining a preset transition process time window in the event of a fault disturbance, and discretizing the preset transition process time window into several time nodes; for each time node, determining the feasible range of reactive power regulation that satisfies the steady-state stability condition and the stability condition under the fault disturbance, based on the reactive power regulation amount of the new energy power plant; constructing a joint feasible domain according to the feasible range of reactive power regulation corresponding to each time node; and determining the target reactive power regulation amount for each new energy power plant within the joint feasible domain.
[0009] According to the reactive power regulation method for new energy power plants provided by the present invention, the step of determining the target reactive power regulation amount of each new energy power plant within the joint feasible domain includes: constructing an objective function based on the reactive power regulation amount of each new energy power plant, the voltage deviation of each node relative to a preset voltage reference value, and the stability margin; solving the objective function under the condition of satisfying the preset regulation constraints and safety constraints of the new energy power plant to obtain an optimized solution result; and determining the target reactive power regulation amount of each new energy power plant based on the optimized solution result.
[0010] According to the reactive power regulation method for new energy power plants provided by the present invention, the step of dividing the nodes in the power grid into control areas based on the regulation influence degree to obtain the control area division result corresponding to each new energy power plant includes: constructing a node regulation influence degree sample set based on the regulation influence degree of reactive power regulation of each new energy power plant on the voltage of each node; clustering the node regulation influence degree sample set to obtain the clustering result of each node; and determining the control area division result corresponding to each new energy power plant based on the clustering result.
[0011] The present invention also provides a reactive power regulation device for a new energy power station, comprising: a data acquisition module for acquiring operating data of the new energy power station and operating data of the power grid, wherein the operating data of the power grid includes the voltage and power of each node; an influence determination module for determining the influence of reactive power regulation of each new energy power station on the voltage of each node based on the operating data of the new energy power station and the operating data of the power grid; a region division module for dividing the nodes in the power grid into control regions based on the influence of regulation, thereby obtaining control region division results corresponding to each new energy power station; a distance characterization module for constructing a stability index for each node based on the voltage of each node, and determining a distance characterization quantity between the operating state of each node and a reference boundary based on the stability index; and an adjustment module for determining the target reactive power regulation amount of each new energy power station based on the control region division results, the distance characterization quantity, and the deviation of the voltage of each node from a preset voltage reference value, and generating a reactive power regulation command corresponding to the new energy power station based on the target reactive power regulation amount.
[0012] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the reactive power control method for new energy power plants as described above.
[0013] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the reactive power control method for new energy power plants as described above.
[0014] The present invention also provides a computer program product, including a computer program, which, when executed by a processor, implements the reactive power control method for new energy power plants as described above.
[0015] The reactive power regulation method and apparatus for new energy power plants provided by this invention obtains operating data of new energy power plants and power grid operating data to determine the degree of influence of reactive power regulation of each new energy power plant on the voltage of each node. Based on the degree of influence, the control area of the nodes in the power grid is divided, thereby distinguishing the voltage support range of different new energy power plants on different nodes. Furthermore, a stability index is constructed based on the voltage of each node, and a distance characterization quantity between the operating state of each node and the reference boundary is determined based on the stability index to characterize the stability of each node. On this basis, combined with the control area division results, the distance characterization quantity, and the deviation of the voltage of each node from the preset voltage reference value, the target reactive power regulation amount of each new energy power plant is determined, and the reactive power regulation command of the corresponding new energy power plant is generated. Therefore, it can improve the rationality of the determination of the target reactive power regulation amount and the effectiveness of node voltage regulation while considering the differences in the voltage effects of different new energy power plants on different nodes. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0017] Figure 1 The flowchart of an example of a reactive power control method for a new energy power station according to the present invention is illustrated schematically. Figure 2 A schematic diagram illustrating the stability index plane and the reference boundary is provided. Figure 3 This schematically illustrates a flowchart of how, according to an embodiment of the present invention, control areas are divided into nodes in the power grid based on the degree of control influence, resulting in control area division results corresponding to each new energy power station. Figure 4 This is a schematic diagram illustrating the control area division of an example of the present invention; Figure 5 This illustration shows a schematic diagram of determining the target reactive power regulation of each new energy power station according to an embodiment of the present invention. Figure 6 This schematically illustrates a flowchart of determining the target reactive power regulation of each renewable energy power station within a joint feasible domain according to an embodiment of the present invention. Figure 7The comparison results of node voltage deviation under different control strategies are shown; Figure 8 The cumulative distribution comparison results of node voltage deviation are shown; Figure 9 This schematic diagram illustrates the structural block diagram of the reactive power control device for new energy power plants provided in an embodiment of the present invention. Figure 10 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0019] In related technologies, the difference in the supporting effect of reactive power regulation of new energy power plants on the voltage of different nodes is not adequately considered during the reactive power regulation process. This makes it difficult to reasonably allocate reactive power regulation resources and accurately determine the target reactive power regulation amount of each new energy power plant, resulting in poor overall power grid regulation effect.
[0020] In view of this, embodiments of the present invention provide a reactive power control method for new energy power plants.
[0021] Figure 1 The flowchart illustrates an example of a reactive power control method for a new energy power station according to the present invention.
[0022] like Figure 1 As shown, the method includes operations S110~S150.
[0023] During operation of S110, data on the operation of new energy power plants and the operation of the power grid are obtained. The power grid operation data includes the voltage and power of each node.
[0024] According to embodiments of the present invention, the operation data of new energy power plants may include data such as active power output, reactive power output, grid connection point voltage, and adjustable reactive power capacity of each new energy power plant, used to characterize the current operating status of each new energy power plant (such as wind power plants, photovoltaic power plants, etc.). Exemplarily, the operation data of new energy power plants can be acquired by a power plant monitoring system and a dispatch automation system.
[0025] According to embodiments of the present invention, power grid operation data may include the voltage of each node, the power of each node, and network topology parameters, used to characterize the current operating state of the power grid. Exemplarily, the power grid operation data may be acquired by a power grid measurement device.
[0026] In operation S120, based on the operation data of the new energy power plants and the power grid operation data, the impact of reactive power regulation of each new energy power plant on the voltage regulation of each node is determined.
[0027] According to an embodiment of the present invention, for a specific renewable energy power station, the degree of influence of the power station on the voltage of each node can be determined based on the voltage changes at the nodes before and after reactive power regulation. Specifically, the degree of influence can characterize the difference in the voltage support capability of the renewable energy power station's reactive power regulation on different nodes. The more significant the voltage change at a node, the stronger the voltage regulation effect of the corresponding renewable energy power station on that node; the smaller the voltage change, the weaker the voltage regulation effect of the corresponding renewable energy power station on that node. Thus, the degree of influence can be used to quantify the strength of the impact of the renewable energy power station's reactive power regulation on the voltage of each node, providing a basis for subsequent control area division.
[0028] According to embodiments of the present invention, the degree of control influence can be calculated by constructing a mapping relationship between the reactive power regulation of each renewable energy power station and the voltage changes of each node. Preferably, the reactive power injection parameters of the renewable energy power station can be introduced into the power flow equation to obtain the voltage response characteristics of each node during the continuous reactive power regulation of the renewable energy power station under the same operating conditions, and the degree of control influence of the reactive power regulation of each renewable energy power station on the voltage of each node can be determined based on the voltage response characteristics.
[0029] For example, to clarify the voltage regulation capability of new energy power stations on each node, let the set of voltage nodes be N, and the set of new energy power stations be G. For any node With any station The impact of reactive power regulation at the g-th renewable energy power station on the voltage regulation of the n-th node can be calculated using the following formula: (1) in Represents a node n The voltage amplitude (or its per-unit value). This represents the amount of reactive power injected (or absorbed) at station g.
[0030] Furthermore, a regulation influence matrix can be constructed for system-level regulation: (2) The matrix described above can be used to describe the impact of changes in reactive power output at new energy power plants on the voltage amplitude of each node.
[0031] Furthermore, to facilitate comparisons between different nodes and stations, and to eliminate the influence of voltage levels and dimensional differences, the control influence matrix is normalized according to the maximum value at each node, thereby obtaining a dimensionless electrical coupling strength index. Specifically, for each node... n Define normalized coupling strength : (3) when When it approaches 1, it indicates that the station g It is a node n The dominant source of control; when A smaller value indicates a weaker impact, which allows us to determine the coupling relationship between each power station and each node, and thus enable targeted regulation of reactive power at new energy power stations.
[0032] In operation S130, based on the degree of influence of regulation, the control areas of the nodes in the power grid are divided to obtain the control area division results corresponding to each new energy power station.
[0033] According to an embodiment of the present invention, a preset normalized coupling strength can be used. The threshold is used to divide the control area.
[0034] According to embodiments of the present invention, since different nodes respond differently to reactive power regulation from renewable energy power plants, nodes with similar levels of regulatory influence can be grouped into the same category through clustering to form different control regions corresponding to the renewable energy power plants. This reflects the differences in the range and strength of voltage support provided by the renewable energy power plants to different nodes.
[0035] In operation S140, stability indices for each node are constructed based on the voltage of each node, and distance characterization quantities between the operating state of each node and the reference boundary are determined based on the stability indices.
[0036] According to an embodiment of the present invention, a stability index is constructed based on the voltage of each node to characterize the stability of node operation, and the corresponding position of each node's operating state in the stability index space is determined based on the stability index. Exemplarily, the stability index space can be a two-dimensional plane or a three-dimensional space.
[0037] The baseline boundary is a reference boundary determined according to the stability discrimination conditions corresponding to the stability index. It is used to characterize the boundary between the stable operating region and the near-instability region of a node in the stability index space.
[0038] Furthermore, based on the distance between the corresponding position of each node's operating state in the stability index space and the baseline boundary, a distance representation quantity between the operating state of each node and the baseline boundary is determined. This distance representation quantity characterizes the degree of proximity between the node's current operating state and the baseline boundary; a smaller distance indicates a smaller stability margin, while a larger distance indicates a larger stability margin.
[0039] In operation S150, based on the control area division results, distance characterization quantities, and the voltage deviation of each node relative to the preset voltage reference value, the target reactive power regulation amount of each new energy power station is determined, and the corresponding reactive power regulation command of the new energy power station is generated according to the target reactive power regulation amount.
[0040] According to embodiments of the present invention, for each new energy power station, the distance characteristics of each node within the control area and the voltage deviation of each node relative to a preset voltage reference value can be obtained. Based on the distance characteristics and the deviation relative to the preset voltage reference value, the target reactive power regulation amount for each new energy power station can be determined. Nodes with smaller distance characteristics indicate that their operating state is closer to the reference boundary and can be given higher regulation priority in the determination of the target reactive power regulation amount; nodes with larger voltage deviations indicate that their voltage deviates more significantly from the preset voltage reference value and can be given higher regulation weight in the determination of the target reactive power regulation amount. Further, based on the determined target reactive power regulation amount, a reactive power regulation command for the corresponding new energy power station is generated and sent to the corresponding new energy power station for reactive power regulation.
[0041] In one implementation, a solution objective can be constructed based on the distance characteristics and voltage deviation of each node within the control area, and the target reactive power regulation of each new energy power station can be obtained under the condition of satisfying the preset regulation constraints and safety constraints of the new energy power station.
[0042] By using the above-mentioned configuration method, the grid nodes are first divided into control areas based on the impact of reactive power regulation of new energy power plants on the voltage of each node. Then, the target reactive power regulation amount is determined by combining the distance between the operating status of each node and the reference boundary, as well as the deviation of the voltage of each node from the preset voltage reference value. This allows for targeted configuration based on the specific conditions of different nodes, enabling reactive power regulation resources to be more concentrated on nodes that require priority support, thereby improving the targeting of reactive power regulation and the voltage support effect of new energy power plants.
[0043] In one illustrative embodiment, an embedding parameter is introduced based on the ground-state power flow solution of the fully embedded method. τ The reactive power injection of new energy power plants is expressed as a function of... τ The problem involves solving for the variation of node voltages using a continuous function form and power series recursion and analytical extension. τ An analytical expression of change. Let the first...r The reactive power of the individual station in the ground state Its expected adjustment increment is Then the parameterized expression for reactive power injection is defined as follows: (4) Based on this, the complex power injection of the station is written as: (5) in, These are embedded parameters used to characterize the parameterized variation process of reactive power injection at renewable energy power plants. It contributes active power to the station in its ground state.
[0044] Compared to traditional methods based on multiple power flow calculations or numerical differences, this approach can simultaneously obtain node voltage state variables and their changing trends during a single analytical recursion process, thereby significantly reducing computational complexity and improving computational consistency.
[0045] In one illustrative embodiment, S140 includes: Based on the voltage of each node, a stability index is constructed for each node, and the stability index of each node is mapped to the stability index plane to determine the mapping position of each node in the stability index plane.
[0046] The distance representation between the corresponding node and the reference boundary in the stability index plane is determined based on the mapping position.
[0047] According to embodiments of the present invention, the voltage of a node can be normalized and mapped to a complex plane—the τ plane. For example, for a load node, the correlation between node voltage and complex power can be constructed using the Thevenin equivalent method, defining a normalized stability index. τ This is used to map the operating states, which are originally dispersed in the time domain and phasor space, onto a unified stability index plane. The normalized voltage can be written in the following form: (6) And define a stability index for complex numbers: (7) in, This is the equivalent external grid voltage of the load node; For equivalent admittance; The voltage at the load node is complex. It is a complex power.
[0048] This mapping allows the time-varying trajectory of a node's voltage to be transformed into the trajectory of a stability index in a plane.
[0049] Run point at The boundary of the plane corresponding to a parabola opening to the right can be used to determine the inequality, which can be written in the form of equation (8): (8) in and These represent the real part and the imaginary part, respectively.
[0050] Furthermore, to quantify the degree to which the operating state of each node approaches the baseline boundary, the minimum distance between the mapping position of each node in the stability index plane and the baseline boundary can be used as a distance representation quantity.
[0051] Figure 2 A schematic diagram of the stability index plane and the reference boundary is shown.
[0052] like Figure 2 As shown, in this plane, based on the boundary conditions derived analytically, it can be clearly stated that when equation (8) holds, the operating point is located within the stable operating region; otherwise, it is located within the potential unstable region. When the operating trajectory gradually approaches the stable boundary, it indicates that the system's stability margin is decreasing; when the trajectory crosses the boundary, it indicates that there is a risk of voltage instability at the node.
[0053] Furthermore, to quantify the degree to which the operating state of each node approaches the baseline boundary, the minimum distance between the mapped position of each node in the stability index plane and the baseline boundary can be used as a distance representation. Let the baseline boundary be... for: (9) In one implementation, when the node's operating state changes over time, let the corresponding coordinates of the node's operating state in the stability index plane be... Then the distance representation quantity It can be represented as: (10) in, Represents the coordinates of a point on the reference boundary; The smaller the value, the higher the time of the node. The closer the operating state is to the baseline boundary, the smaller the corresponding stability margin; The larger the value, the higher the time of the node. The further the operating state is from the baseline boundary.
[0054] In embodiments of the present invention, for multi-node systems, a virtual branch equivalence method is used to achieve network decoupling, transforming the complex network into several equivalent two-node subsystems. This allows the running trajectories of all nodes in the system to be plotted against a unified baseline boundary. τWithin the plane, a unified quantitative assessment of the stability margin of all nodes in the system is achieved. This is especially relevant when certain critical nodes in the system... τ When the trajectory continues to approach the boundary and crosses the stable boundary curve, it indicates that the system has exceeded the steady-state stability limit, and the risk of voltage collapse has increased significantly.
[0055] For example, the voltage trajectory of a node is obtained by using a fully embedded method. τ Analyzing the evolution process in the plane reveals that when the node trajectory approaches or crosses the steady-state boundary, the system faces a high risk of transient voltage collapse. As the system load level increases or fault disturbances occur, the line transmission power continuously increases, and the voltage at the nodes along the line exhibits a monotonically decreasing trend. The load side has the weakest voltage support capacity and the largest voltage drop. When the operating point crosses the power-voltage characteristic critical point, the system will enter a positive feedback process of "voltage decrease - current increase - line loss increase - voltage further decrease," which can easily trigger voltage collapse.
[0056] Projecting this evolutionary process onto τ The plan view shows some key nodes. τ The trajectory rapidly approaches or even crosses the reference boundary during the disturbance process, indicating that the reference boundary of each node can effectively characterize the voltage stability characteristics limit after the disturbance, providing clear theoretical support for the subsequent voltage instability protection criteria based on the running trajectory.
[0057] In one illustrative embodiment, operation S140 further includes: determining a disturbance correction coefficient based on the voltage drop of each node under the current operating conditions, and correcting the reference boundary based on the disturbance correction coefficient.
[0058] Specifically, the aforementioned benchmark boundary can be used to characterize the stability discrimination boundary of the node operating state under steady-state conditions. However, during the transition process after a fault disturbance, the voltage of each node may dynamically drop, and the benchmark boundary under steady-state conditions alone is insufficient to fully reflect the safety margin of the node operating state under disturbance. Based on this, a disturbance correction coefficient can be introduced to correct the benchmark boundary so that the corrected boundary can characterize the node voltage safety boundary during the transition process after a fault disturbance.
[0059] Furthermore, the disturbance correction factor can be determined based on the voltage drop amplitude of each node under the current operating conditions. The larger the voltage drop amplitude, the more significant the impact of the fault disturbance on the node's operating state; correspondingly, the smaller the disturbance correction factor. Conversely, the smaller the voltage drop amplitude, the less affected the node is by the disturbance; correspondingly, the disturbance correction factor is closer to 1. Thus, the reference boundary can be adaptively tightened according to different disturbance degrees.
[0060] The corrected datum boundary can be represented as: (11) Among them, the disturbance correction coefficient ∈(0,1], taken during unperturbed steady-state operation =1, corresponding to the steady-state reference boundary; after a fault disturbance, when the fault disturbance causes a drop in node voltage, The corrected boundary is tightened relative to the reference boundary into the stable region, thereby reserving a safety margin for voltage drop during the transition process.
[0061] In this way, the distance representation can not only reflect the proximity between the node's operating state and the steady-state reference boundary, but also the proximity between the node's operating state and the corrected reference boundary under fault disturbance.
[0062] Figure 3 The flowchart illustrates a process according to an embodiment of the present invention, in which control areas are divided into nodes in the power grid based on the degree of control influence, to obtain control area division results corresponding to each new energy power station.
[0063] like Figure 3 As shown, operation S130 includes operations S310 to S330.
[0064] In operating S310, a sample set of node regulation influence is constructed to assess the impact of reactive power regulation of each new energy power station on the voltage regulation of each node.
[0065] According to an embodiment of the present invention, firstly, for the new energy power station a to be divided, a node regulation influence sample set can be constructed based on its influence on the voltage regulation of each node: , in n This represents the total number of nodes in the power grid.
[0066] In operation S320, the sample set of node regulation influence is clustered to obtain the clustering results of each node.
[0067] According to an embodiment of the present invention, for a sample set of node regulation influence corresponding to any renewable energy power station, clustering can be used to group the nodes in the sample set, so that nodes with similar regulation influence are classified into the same category. Since the regulation influence corresponding to different nodes varies, clustering can identify the distribution of the strength of the renewable energy power station's voltage support effect on different nodes, thereby obtaining the clustering results of each node.
[0068] In one example, multiple candidate partition numbers can be preset, and clustering processing can be performed on the node control influence sample set for each candidate partition number to obtain clustering results under different candidate partition numbers. For example, the candidate partition numbers K=2, K=3, and K=4 can be set respectively, and K-means clustering can be performed on the node control influence sample set to obtain clustering results under different candidate partition numbers.
[0069] According to embodiments of the present invention, the target number of partitions can be determined by calculating clustering evaluation indices corresponding to different candidate partitions. For example, the silhouette coefficient is used as the clustering evaluation index; a larger silhouette coefficient indicates better cluster compactness and inter-class separation of the corresponding clustering result. Therefore, the candidate partition number corresponding to the maximum silhouette coefficient can be selected as the target number of partitions under the current operating condition, and the clustering result under this target number of partitions can be used as the clustering result for each node.
[0070] In operation S330, based on the clustering results, the control area division results corresponding to each new energy power station are determined.
[0071] According to an embodiment of the present invention, the grouping of nodes corresponding to new energy power stations can be determined based on the category affiliation of each node in the clustering results, and different node groups can be determined as different control areas corresponding to new energy power stations, thereby obtaining the control area division results corresponding to new energy power stations.
[0072] In one example, when the target number of partitions K=2, the clustering results can be divided into two control regions. The categories with higher regulatory influence correspond to the strongly coupled control region, while those with lower influence correspond to the weakly coupled collaborative region. Nodes in the strongly coupled control region are more sensitive to reactive power regulation responses from renewable energy power plants and are therefore priority targets for regulation, serving as key control areas for reactive power optimization and emergency protection. Nodes in the weakly coupled collaborative region have relatively weaker reactive power regulation responses from renewable energy power plants and primarily play a supporting and collaborative regulatory role.
[0073] In one example, when the target number of partitions When the clustering coefficient is 3, the clustering results can be divided into three control regions. The category with the highest control influence corresponds to the strongly coupled control region, the category with moderate control influence corresponds to the second strongly coupled collaborative region, and the category with low control influence corresponds to the weakly coupled collaborative region. The strongly coupled control region is used for priority control; nodes in the second strongly coupled collaborative region have good response capabilities to reactive power regulation of new energy power plants and can serve as auxiliary collaborative objects in the core control region, participating in collaborative optimization under steady-state conditions and supplementing reactive power support under disturbance conditions; nodes in the weakly coupled collaborative region have relatively weak responses and mainly undertake low-priority collaborative regulation roles.
[0074] Figure 4 This is a schematic diagram illustrating the control area division of an example of the present invention.
[0075] like Figure 4 As shown, when the target number of partitions When the clustering coefficient is 4, the clustering results are divided into four control regions. The category with the highest control influence corresponds to the strongly coupled control region, the second highest corresponds to the second strongest coupled coordination region, the lowest corresponds to the weakly coupled coordination region, and the lowest corresponds to the weakly coupled monitoring region. The strongly coupled control region and the second strongest coupled coordination region are used for high-priority control and auxiliary coordinated control, respectively. The weakly coupled coordination region mainly serves as an emergency backup coordination target, and under steady-state conditions, it does not participate in reactive power optimization regulation, but plays an auxiliary support role under node voltage exceedance or system disturbance conditions. The nodes in the weakly coupled monitoring region have weak electrical coupling with the new energy power station and are not included in the optimization control range under normal operating conditions; they are only used as monitoring targets for voltage stability margin.
[0076] By using the above method, the number of control areas can be adaptively determined based on the distribution characteristics of the node regulation influence sample set under different operating conditions, and different control areas can correspond to different regulation priorities and action modes, thereby improving the matching degree between the control area division results and the distribution of voltage support effect of new energy power stations.
[0077] Figure 5 The illustration shows a schematic diagram of determining the target reactive power regulation of each new energy power station according to an embodiment of the present invention.
[0078] like Figure 5 As shown, operation S150 includes operations S510 to S540.
[0079] When operating S510, in the event of a fault disturbance, a preset transition process time window is determined and the preset transition process time window is discretized into several time nodes.
[0080] According to an embodiment of the present invention, after a fault disturbance occurs, the system operating state typically undergoes a transition process from a disturbed state to a restored steady-state state. To ensure that the subsequently determined target reactive power regulation not only meets the steady-state operation requirements but also the operational safety requirements after the fault disturbance, a preset transition process time window can be determined after the fault disturbance occurs, and this preset transition process time window can be discretized into several time nodes to allow for separate analysis of multiple moments during the transition process.
[0081] Among them, fault disturbance refers to disturbance events caused by power grid faults, sudden changes in operating mode or other abnormal operating conditions, which cause the power grid to enter a transition process from the original steady-state operating state and result in dynamic drops or fluctuations in node voltage.
[0082] When operating S520, for each time node, based on the reactive power regulation of the new energy power station, the feasible range of reactive power regulation that meets the steady-state stability condition and the stability condition under fault disturbance is determined respectively.
[0083] According to embodiments of the present invention, the reactive power regulation of new energy power plants at various time points can be analyzed separately, and it can be determined whether the reactive power regulation of the new energy power plants simultaneously satisfies both steady-state stability conditions and stability conditions under fault disturbances. Specifically, when the distance between the node's operating state and the steady-state reference boundary is greater than a preset steady-state threshold, the steady-state stability condition is considered satisfied; when the distance between the node's operating state and the reference boundary after disturbance correction is greater than a preset disturbance threshold, the stability condition under fault disturbances is considered satisfied. The range of reactive power regulation values satisfying both steady-state stability conditions and stability conditions under fault disturbances can be taken as the feasible range of reactive power regulation at the corresponding time point.
[0084] When operating S530, a joint feasible domain is constructed based on the feasible range of reactive power adjustment corresponding to each time node.
[0085] According to an embodiment of the present invention, since different time nodes correspond to different feasible ranges of reactive power adjustment, in order to ensure that the target reactive power adjustment amount continuously meets the steady-state stability condition and the stability condition under fault disturbance within the preset transition process time window, the feasible ranges of reactive power adjustment corresponding to each time node can be combined to obtain a joint feasible domain.
[0086] Specifically, at each time node, reactive power regulation boundaries satisfying both steady-state stability conditions and stability conditions under fault disturbances can be determined, thus forming two-dimensional feasible boundaries corresponding to each time node. Furthermore, by combining the two-dimensional feasible boundaries corresponding to each time node along the time axis, a joint feasible region corresponding to a preset transition process time window can be formed. The inner region of the joint feasible region is the reactive power regulation feasible interval where the system simultaneously satisfies both steady-state stability requirements and stability requirements under fault disturbances.
[0087] In operating S540, the target reactive power regulation of each new energy power station is determined within the joint feasible domain.
[0088] According to an embodiment of the present invention, a solution objective can be constructed based on the deviation of the voltage of each node from a preset voltage reference value, the distance characterization quantity, and the reactive power regulation quantity of the new energy power station, and the reactive power regulation quantity of the new energy power station can be solved within the joint feasible domain to obtain the target reactive power regulation quantity of each new energy power station.
[0089] By adopting the above method, we can avoid determining the target reactive power regulation based solely on a single steady-state moment, while ignoring the safety requirements of the transient process after fault disturbances, thereby improving the adaptability of the target reactive power regulation determination result to complex operating conditions.
[0090] Figure 6 The flowchart illustrating the determination of target reactive power regulation for each renewable energy power station within a joint feasible domain is shown in one embodiment of the present invention.
[0091] like Figure 6 As shown, operation S540 includes operations S610~S630.
[0092] When operating S610, an objective function is constructed based on the reactive power regulation of each new energy power station, the voltage deviation of each node relative to the preset voltage reference value, and the stability margin.
[0093] According to an embodiment of the present invention, after the joint feasible region has been determined, it is necessary to further optimize the candidate reactive power regulation quantities within the joint feasible region to obtain the target reactive power regulation quantities for each new energy power station. To this end, an objective function for optimization within the joint feasible region can be constructed by comprehensively considering the stability performance corresponding to the candidate reactive power regulation quantities, the voltage deviation of each node relative to a preset voltage reference value, and the reactive power regulation cost of the new energy power station.
[0094] In one example, a comprehensive stability margin can be used. The stability of candidate reactive power regulation quantities under steady-state operation and fault disturbance conditions can be characterized by: (12) in, This refers to the steady-state voltage stability margin. This represents the probability of steady-state voltage exceeding its limit. This refers to the voltage sag margin during the transient process. For the transient process, the power angle stability margin; , , , The normalized weighting coefficients are determined through training on typical power grid operation scenarios.
[0095] Specifically, steady-state voltage stability margin Used to characterize the safety margin of a system relative to the voltage instability boundary under steady-state operating conditions; probability of steady-state voltage exceeding the limit. This is used to characterize the risk of node voltages exceeding the allowable range under steady-state conditions. It can be calculated based on historical operating data and combined with the node voltages at the current operating point; voltage sag margin during transient processes. Used to characterize the safety margin of node voltage relative to the aforementioned boundary during the transition process after a fault disturbance, it can be used in Represented by the distance from the boundary on the plane; transient process power angle stability margin. It is used to characterize the stability of the system's power angle during the transition process after a fault disturbance, and can be used to reflect the dynamic change characteristics of the generator rotor power angle.
[0096] In one example, let the set of nodes be... L New energy power stations are integrated into G Then, the following objective function can be used to optimize the solution within the joint feasible region: (13) in, For nodes b Voltage deviation weighting coefficient; For nodes b The actual voltage; Represents a node b The preset voltage reference value; Indicates new energy power station a The unit reactive power regulation cost; Indicates new energy power station a The reactive power regulation; Indicates new energy power station a The ground-state reactive power regulation.
[0097] By operating S620, under the condition of satisfying the preset adjustment constraints and safety constraints of the new energy power station, the objective function is solved to obtain the optimized solution result.
[0098] According to an embodiment of the present invention, after constructing the objective function, it is also necessary to solve the objective function under the constraints of the actual regulation capacity of the new energy power station and the system operation safety requirements, so as to avoid obtaining reactive power regulation amounts that exceed the actual regulation capacity of the new energy power station or do not meet the system safety requirements.
[0099] For example, preset adjustment constraints may include: (14) in, and They represent new energy power stations. a The lower limit and upper limit of reactive power regulation.
[0100] Safety constraints may include: (15) in, and Representing nodes respectively b The lower and upper voltage limits.
[0101] When operating S630, the target reactive power regulation of each new energy power station is determined based on the optimization solution results.
[0102] According to an embodiment of the present invention, after optimizing the objective function, an optimized solution that satisfies preset adjustment constraints and safety constraints can be obtained. Furthermore, the reactive power regulation amount of the new energy power station that makes the objective function reach the value corresponding to the optimized result can be determined as the target reactive power regulation amount for each new energy power station.
[0103] In one illustrative embodiment, a voltage instability protection activation criterion can also be constructed based on the distance change between the node's running trajectory and the dynamic reference boundary.
[0104] According to an embodiment of the present invention, during the transition process following a fault disturbance, if the operating state of a node continues to approach the aforementioned reference boundary corrected by the disturbance correction coefficient, it indicates that the system is at risk of further deterioration and voltage instability. Therefore, the operating trajectory of the node in the stability index plane can be monitored, and the decision to activate voltage instability protection can be made based on the change in distance between the node and the dynamic safety boundary.
[0105] In one example, let the node to be monitored be node . c ,node c The corresponding stability index under the current operating state is: The boundary after correction by the disturbance correction factor is denoted as Then the node c Minimum distance between the corrected boundary It can be defined as: (16) Furthermore, a distance reference threshold can be set. and duration threshold When a node simultaneously meets the following conditions, it can be determined that the system has a risk of voltage instability, and voltage instability protection will be activated: , <0、 (17) in, This indicates the minimum distance between the node and the reference boundary. The duration of the state where "the distance is still decreasing".
[0106] Based on the above criteria, when a node simultaneously meets the distance threshold condition, the distance change trend condition, and the duration condition, it can be considered that the system has experienced voltage instability risk during the transition process, and corresponding voltage instability protection measures will be activated. These protection measures may include at least one of the following: outputting emergency reactive power support commands, increasing the priority of reactive power regulation at renewable energy power plants, and switching to emergency support control mode.
[0107] Figure 7The results show a comparison of node voltage deviations under different control strategies.
[0108] Depend on Figure 7 It can be seen that after adopting the reactive power regulation method of the new energy power station of the present invention, the deviation of the node voltage relative to the reference value is reduced as a whole, which is manifested in the suppression of the peak deviation of the node and the reduction of the number of nodes with large deviation.
[0109] Figure 8 The cumulative distribution comparison results of node voltage deviation are shown.
[0110] Depend on Figure 8 It can be seen that, under the same deviation threshold, the cumulative probability corresponding to the present invention is higher, indicating that the voltage deviation of more nodes is controlled within a smaller range; at the same time, in the larger deviation range, the curve corresponding to the present invention approaches 1 faster, indicating that the proportion of nodes with larger voltage deviations is further reduced.
[0111] The reactive power control device for new energy power plants provided by the present invention is described below. The reactive power control device for new energy power plants described below and the reactive power control method for new energy power plants described above can be referred to in correspondence.
[0112] Figure 9 The schematic diagram illustrates the structural block diagram of the reactive power control device for new energy power plants provided in an embodiment of the present invention.
[0113] like Figure 9 As shown, the reactive power control device 900 for new energy power plants includes a data acquisition module 910, an impact determination module 920, a region division module 930, a distance characterization module 940, and an adjustment module 950.
[0114] The data acquisition module 910 is used to acquire the operation data of the new energy power station and the power grid operation data. The power grid operation data includes the voltage and power of each node.
[0115] The impact determination module 920 is used to determine the impact of reactive power regulation of each new energy power station on the voltage regulation of each node based on the operation data of the new energy power station and the power grid operation data.
[0116] The region division module 930 is used to divide the control regions of nodes in the power grid according to the degree of control impact, and obtain the control region division results corresponding to each new energy power station.
[0117] The distance characterization module 940 is used to construct the stability index of each node based on the voltage of each node, and to determine the distance characterization quantity between the operating state of each node and the reference boundary based on the stability index.
[0118] The adjustment module 950 is used to determine the target reactive power adjustment amount of each new energy power station based on the control area division results, distance characterization quantity, and the voltage deviation of each node relative to the preset voltage reference value, and to generate the corresponding reactive power adjustment command for the new energy power station based on the target reactive power adjustment amount.
[0119] Figure 10 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7 As shown, the electronic device may include a processor 1010, a communications interface 1020, a memory 1030, and a communication bus 1040. The processor 1010, communications interface 1020, and memory 1030 communicate with each other via the communication bus 1040. The processor 1010 can call logic instructions from the memory 1030 to execute reactive power control methods for renewable energy power plants.
[0120] Furthermore, the logical instructions in the aforementioned memory 1030 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part 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 of the various embodiments of the present invention. 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.
[0121] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the reactive power control method for new energy power plants provided by the above methods.
[0122] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the reactive power control methods for new energy power plants provided by the above methods.
[0123] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0124] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.
[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A reactive power control method for new energy power plants, characterized in that, include: Acquire operational data of new energy power plants and power grid operation data, wherein the power grid operation data includes the voltage and power of each node; Based on the operation data of the new energy power plants and the operation data of the power grid, determine the degree of influence of reactive power regulation of each new energy power plant on the voltage regulation of each node; Based on the aforementioned regulatory impact, control areas are divided for nodes in the power grid to obtain control area division results corresponding to each new energy power station. Based on the voltage of each node, a stability index for each node is constructed, and a distance characterization quantity between the operating state of each node and the reference boundary is determined based on the stability index. Based on the control area division results, the distance characterization quantity, and the voltage deviation of each node relative to the preset voltage reference value, the target reactive power regulation amount of each new energy power station is determined, and the corresponding reactive power regulation command of the new energy power station is generated according to the target reactive power regulation amount.
2. The reactive power control method for new energy power plants according to claim 1, characterized in that, The process of constructing stability indices for each node based on its voltage, and determining the distance representation quantity between the operating state of each node and the reference boundary based on the stability indices, includes: Based on the voltage of each node, a stability index corresponding to each node is constructed, and the stability index corresponding to each node is mapped to a stability index plane to determine the mapping position of each node in the stability index plane. The distance representation quantity between the corresponding node and the reference boundary in the stability index plane is determined based on the mapping position.
3. The reactive power control method for new energy power plants according to claim 1, characterized in that, The process of constructing stability indices for each node based on its voltage, and determining the distance representation between the operating state of each node and the reference boundary based on the stability indices, further includes: The disturbance correction coefficient is determined based on the voltage drop of each node under the current operating conditions, and the reference boundary is corrected based on the disturbance correction coefficient.
4. The reactive power control method for new energy power plants according to claim 1, characterized in that, Determining the target reactive power regulation for each new energy power station includes: In the event of a fault disturbance, a preset transition process time window is determined, and the preset transition process time window is discretized into several time nodes; For each of the aforementioned time points, based on the reactive power regulation of the new energy power station, the feasible range of reactive power regulation that satisfies the steady-state stability condition and the stability condition under fault disturbance is determined respectively. Construct a joint feasible domain based on the feasible range of reactive power adjustment corresponding to each of the aforementioned time nodes; Within the joint feasible domain, determine the target reactive power regulation of each new energy power station.
5. The reactive power control method for new energy power plants according to claim 4, characterized in that, Determining the target reactive power regulation of each renewable energy power station within the joint feasible domain includes: The objective function is constructed based on the reactive power regulation of each new energy power station, the voltage deviation of each node relative to the preset voltage reference value, and the stability margin. Under the condition of satisfying the preset adjustment constraints and safety constraints of the new energy power station, the objective function is solved to obtain the optimized solution result; Based on the optimization results, the target reactive power regulation of each new energy power station is determined.
6. The reactive power control method for new energy power plants according to claim 1, characterized in that, The process of dividing the nodes in the power grid into control areas based on the aforementioned regulatory impact degree, and obtaining the control area division results corresponding to each new energy power station, includes: To assess the impact of reactive power regulation at various renewable energy power plants on voltage regulation at each node, a sample set of node regulation impact values is constructed. Cluster the sample set of node regulation influence to obtain the clustering results for each node; Based on the clustering results, the control area division results corresponding to each new energy power station are determined.
7. A reactive power control device for a new energy power station, characterized in that, include: The data acquisition module is used to acquire the operation data of the new energy power station and the power grid operation data, wherein the power grid operation data includes the voltage and power of each node; The impact determination module is used to determine the impact of reactive power regulation of each new energy power station on the voltage regulation of each node based on the operation data of the new energy power station and the operation data of the power grid. The region division module is used to divide the control regions of nodes in the power grid according to the control influence degree, and obtain the control region division results corresponding to each new energy power station. The distance characterization module is used to construct the stability index of each node based on the voltage of each node, and to determine the distance characterization quantity between the operating state of each node and the reference boundary based on the stability index. The adjustment module is used to determine the target reactive power adjustment amount for each new energy power station based on the control area division result, the distance characterization quantity, and the voltage deviation of each node relative to the preset voltage reference value, and to generate the corresponding reactive power adjustment command for the new energy power station based on the target reactive power adjustment amount.
8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the reactive power control method for new energy power plants as described in any one of claims 1 to 6.
9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the reactive power control method for new energy power plants as described in any one of claims 1 to 6.
10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the reactive power control method for new energy power plants as described in any one of claims 1 to 6.