A multi-type network equipment optimization configuration method for large-scale new energy power grid voltage support

Abstract

The application discloses a multi-type network equipment optimization configuration method for large-scale new energy power grid voltage support, and relates to the technical field of new energy power grid planning and power system optimization. The method comprises the following steps: establishing a multi-type network equipment parameterization representation framework considering short-circuit capacity support capability and comprehensive economic cost, and constructing a relationship model of multi-type network equipment for improving short-circuit ratio of new energy multi-station based on short-circuit capacity support; proposing a new energy multi-station short-circuit ratio analytical constraint considering a new steady-state voltage operating point, and constructing a multi-type network equipment optimization configuration model according to the constraint; and proposing a hierarchical partition system of "anchor point-root node-station group" and a Schur network equivalence method, so as to form an accelerated solution method for the large-scale power grid configuration optimization problem. The method can realize the optimization configuration of multi-type network equipment under a large-scale new energy power grid, ensure that new energy stations have sufficient voltage support capability, and take into account the economy of equipment configuration.

Description

Technical Field

[0001] This invention relates to the field of new energy power grid planning and power system optimization technology, specifically to a method for optimizing the configuration of multiple types of grid-building equipment for voltage support in large-scale new energy power grids. Background Technology

[0002] The installed capacity and penetration rate of new energy sources such as wind power and photovoltaics continue to increase. Large-scale new energy units are connected to the grid via power electronic interfaces and are gradually replacing traditional synchronous generator units. Unlike traditional synchronous power sources, new energy units have low inertia, weak transient support capabilities, and are more sensitive to changes in grid strength. As new energy sources encroach on the operating space of conventional synchronous power sources, the grid's short-circuit capacity decreases and its voltage support capability weakens, exhibiting obvious characteristics of a weak grid. Under weak grid conditions, the reliable transmission of new energy power and the safe and stable operation of new energy power plants face significant risks.

[0003] The multiple renewable energy station short circuit ratio (MRSCR) is an important indicator characterizing the voltage support strength and disturbance rejection capability of renewable energy stations at their grid connection points. It reflects the system support level after multiple renewable energy stations are coupled through an AC network. To improve voltage support capability in weak grid areas, various types of grid-connected equipment, such as synchronous condensers, grid-based reactive power support devices, and grid-based energy storage, can be configured in the grid to enhance short-circuit capacity support and improve MRSCR. Compared to single-type equipment, multiple types of grid-connected equipment have their own advantages in terms of support characteristics, response speed, applicable scenarios, and overall economic efficiency. However, they also have problems such as complex configuration relationships, high investment costs, and difficulty in coordinated optimization.

[0004] Therefore, for large-scale renewable energy power grids, given the MRSCR improvement target of renewable energy power plants, how to comprehensively consider the short-circuit capacity support capability, access location and comprehensive economic cost of various types of grid-connecting equipment, establish an MRSCR constraint expression that can be embedded in optimization solution, and realize the efficient optimization configuration of various types of grid-connecting equipment under large-scale power grid conditions has become a key technical problem that urgently needs to be solved in the field of renewable energy power grid planning and power system optimization. Summary of the Invention

[0005] The purpose of this invention is to provide an optimized configuration method for multiple types of grid-building equipment for voltage support in large-scale new energy power grids, in order to solve the technical problems in the prior art, such as the difficulty in uniformly representing the short-circuit capacity support capability and comprehensive economic cost of multiple types of grid-building equipment, the difficulty in embedding MRSCR constraints into the optimized configuration model, and the excessively large scale of solving large-scale power grid configuration optimization problems.

[0006] Furthermore, this invention also aims to solve the following technical problems: how to characterize the role of different types of grid-connecting equipment in improving MRSCR under a unified optimization framework; how to establish analytical constraints on MRSCR under the condition of considering the new steady-state voltage operating point of new energy power plants; and how to accelerate the solution of the large-scale new energy power grid equipment optimization configuration problem by using the hierarchical partitioning system of "anchor point-root node-field group" and the Schur network equivalent method, while retaining the influence of electrical coupling of the entire network.

[0007] To achieve the above objectives, this invention provides a method for optimizing the configuration of multiple types of grid-connected equipment for voltage support in large-scale renewable energy power grids. First, this method establishes a parameterized characterization framework for multiple types of grid-connected equipment, considering both short-circuit capacity support and overall economic cost, to uniformly describe the impact of different types of equipment on MRSCR improvement. Then, based on the new steady-state voltage operating point of renewable energy power plants, analytical constraints on MRSCR are established, and an optimization configuration model for multiple types of grid-connected equipment is constructed accordingly. Furthermore, considering the large scale of the solution to the large-scale renewable energy power grid configuration optimization problem, a hierarchical partitioning system of "anchor point-root node-power plant cluster" is constructed, and combined with the Schur network equivalent method, an accelerated solution method for large-scale power grids is formed, thereby obtaining an optimized configuration scheme for multiple types of grid-connected equipment that meets the voltage support requirements of renewable energy power plants while also considering the economic efficiency of equipment configuration.

[0008] Firstly, this invention provides a parameterized characterization method for multiple types of grid-connected equipment oriented towards voltage support for large-scale renewable energy power grids. This method establishes a parameterized characterization framework for multiple types of grid-connected equipment that considers short-circuit capacity support capability and comprehensive economic costs, and characterizes the actual installed capacity of different types of grid-connected equipment. Short-time overload capacity or equivalent short-circuit support coefficient Comprehensive economic costs The available access locations are described in a unified manner, thereby characterizing the support characteristics and economic differences of different types of network equipment under the same optimization framework.

[0009] For any device catalog item Its equivalent short-circuit support capability Defined as:

[0010]

[0011] in, Indicates device catalog item The corresponding equivalent short-circuit support capacity. Through the above definition, a distinction is made between the actual installed capacity for engineering configuration and the equivalent short-circuit support capacity for voltage support analysis, thus providing a unified description of the differences in short-circuit capacity support among different types of network equipment.

[0012] Furthermore, let the set of candidate access locations be... The device catalog collection is For any candidate access location and any device catalog item Define device selection variables When candidate access location Select the device configuration catalog item. hour, ,otherwise Then the candidate access location The equivalent short-circuit support factor introduced by the equipment configuration can be expressed as:

[0013]

[0014] in, As the system's baseline capacity, Indicates candidate access location The equivalent short-circuit support increment is formed by the configured network equipment.

[0015] Based on the above parameterized characterization, this invention further establishes the relationship between various types of network equipment and MRSCR improvement. Let the baseline admittance matrix of the regional network be... Then the regional network admittance matrix after the device is connected can be expressed as:

[0016]

[0017] in, This is a vector composed of the equivalent short-circuit support coefficients of each candidate access location. It can be seen that various types of network-connected equipment affect the electrical coupling relationship and voltage support strength between new energy power stations by altering the network admittance structure.

[0018] Therefore, this invention achieves unified modeling and collaborative configuration of multiple types of network equipment under the same optimization framework through the mapping chain of "actual installed capacity - equivalent short-circuit support capability - network admittance change - MRSCR improvement".

[0019] Secondly, this invention provides a method for constructing analytical constraints for MRSCR (Mean Static Voltage Ratio) considering the new steady-state voltage operating point of renewable energy power plants, and based on this, constructs an optimal configuration model for multiple types of network equipment. The core of this method lies in: while preserving the influence of the steady-state voltage ratio among renewable energy power plants, reconstructing the MRSCR constraints into network equation constraints and cone constraints suitable for optimization, thereby enabling the MRSCR to be directly embedded into the optimal configuration model for multiple types of network equipment.

[0020] Let the collection of new energy power stations be... , , and They represent new energy power stations. The steady-state grid connection point voltage, rated voltage, and new energy injection power. Let the elements of the equivalent impedance matrix on the busbar subspace of the power station represent the new energy power station. The MRSCR can be expressed as:

[0021]

[0022] As can be seen from the above equation, the MRSCR is not only affected by the impedance coupling between power plants, but also explicitly includes the steady-state voltage ratio term between different renewable energy power plants. Therefore, under a given planned operating condition or the current closed-loop replacement operating point, this invention treats the steady-state voltage phasor of the renewable energy power plant as a known parameter, and retains the influence of the steady-state voltage ratio term on the MRSCR.

[0023] Furthermore, define the steady-state voltage conjugate diagonal matrix. and new energy injection vector The coupled response corresponding to the denominator term of MRSCR is defined as the virtual voltage response vector. Then we have:

[0024]

[0025] Therefore, new energy power stations The MRSCR can be reconstructed as follows:

[0026]

[0027] in, For new energy power stations The steady-state grid connection point voltage, For new energy power stations Rated voltage, For new energy power stations The corresponding virtual voltage response, not the new energy power station. The actual operating voltage. To avoid explicitly handling the impedance matrix inversion in the optimization model, this invention further defines the voltage ratio corrected admittance matrix:

[0028]

[0029] The virtual voltage response vector then satisfies the following equivalent linear network equation:

[0030]

[0031] Generalize the above results to the entire set of retained buses. .in, Let be the reference admittance matrix after voltage ratio correction. Let the total network injection vector be... The virtual voltage response vector is Then the network balance relationship can be written as:

[0032]

[0033] Furthermore, Decompose into real and imaginary parts, denoted as and will Decomposed into The complex power is decomposed into active power and reactive power, denoted as: The network equilibrium relationship can then be further transformed into real and virtual part constraints:

[0034]

[0035] For new energy power station clusters that require explicit verification ,definition:

[0036]

[0037] If new energy power stations The target MRSCR threshold is Then its MRSCR constraint can be written as:

[0038]

[0039] Furthermore, by solving the above constraints in terms of their real and imaginary parts, we can obtain the second-order cone-shaped constraints:

[0040]

[0041] Therefore, this invention reconstructs the MRSCR constraint into an analytical expression of "modified admittance network equation + second-order cone constraint", thereby enabling the constraint to be directly embedded into the optimization configuration model of multiple types of network devices.

[0042] Based on this, this invention constructs an optimization configuration model for multiple types of network construction equipment, with the goal of minimizing the overall economic cost of network construction equipment. The objective function is:

[0043]

[0044] The investment costs, operation and maintenance costs, and arbitrage of different capacities and types of network equipment are all included in the annual comprehensive cost of the equipment. middle.

[0045] The above technical solution achieves a unified expression of MRSCR constraints in the optimization configuration problem of multiple types of network devices.

[0046] Thirdly, this invention provides an accelerated solution method for the configuration optimization problem of large-scale renewable energy power grids based on a hierarchical partitioning system of "anchor point-root node-field cluster" and the equivalent Schur network. This method addresses the challenges of a large number of renewable energy power plants, numerous candidate network connection locations, and a large overall network optimization model in large-scale renewable energy power grids. By constructing a hierarchical partitioning system and preserving the equivalent influence of external networks within each partition, it achieves dimensionality reduction and accelerated solution to the optimization configuration problem of multiple types of network connection equipment while ensuring that the electrical coupling relationship of the entire network is not disrupted.

[0047] Furthermore, let the power grid topology be denoted as an undirected graph. ,in Represents the set of power grid nodes. The set of power grid branches and the set of new energy power station access busbars are denoted as . This invention first constructs a hierarchical partitioning system of "anchor point-root node-field group". The anchor point set is as follows: The root node set is Then the set of anchor points and the set of root nodes are defined as follows:

[0048]

[0049] in, Represents a node voltage level, This indicates the minimum voltage level threshold corresponding to the anchor point. This represents the minimum voltage level threshold corresponding to the root node, and .

[0050] Furthermore, record For nodes and nodes In the power grid topology diagram Given the shortest path length, the mapping relationships from the new energy power station to the anchor point and from the anchor point to the root node are defined as follows:

[0051]

[0052] as well as

[0053]

[0054] This forms a hierarchical ownership chain among new energy power stations, anchor points, and root nodes. This will allow new energy power stations with similar support transmission paths and similar backbone network affiliations to be prioritized for clustering.

[0055] Furthermore, within the same root node's watershed, anchor points with similar electrical connections are clustered to form field group partitions. Let... Represents the root node The corresponding number If there are several anchor point clusters, then the corresponding set of new energy power station clusters can be represented as:

[0056]

[0057] This results in a cluster partitioning unit with the root node as the backbone level, the anchor point cluster as the local support channel, and the new energy power station set as the optimization object, thus obtaining a partitioning optimization unit suitable for local modeling and local solution.

[0058] Furthermore, to avoid neglecting the impact of external networks on voltage support of renewable energy power plants within a partition due to relying solely on localized partition network extraction, this invention establishes Schur network equivalence relationships for each partition. Let the set of retained buses for any active partition be... The set of external elimination busbars in the partition is The entire network modified admittance matrix can be re-divided into blocks according to the retained bus and the elimination bus, which can be written as:

[0059]

[0060] exist Under reversible conditions, the external network of the partition can be eliminated, and the Schur network equivalence relation of the partition can be obtained. That is, the equivalence admittance matrix and equivalence injection vector of the partition are expressed as follows:

[0061]

[0062] Therefore, although the external network of the partition no longer participates in the solution of the partition subproblem as an explicit optimization variable, its electrical coupling effect on the reserved bus inside the partition is still reflected through the equivalent admittance matrix. and equivalent injection vector This is preserved, thus ensuring consistency between the local optimization problem and the original network background of the entire network.

[0063] Furthermore, in a partitioned equivalent network, the network configuration is still entered into the regional admittance matrix in the form of diagonal increments on the partition-reserved bus. Therefore, the partitioned optimization model can be written as:

[0064]

[0065] And satisfy the following partition network balance relationship:

[0066]

[0067] Furthermore, based on the aforementioned hierarchical partitioning system and the Schur network equivalence relation, this invention constructs optimization sub-problems for each partition and solves these sub-problems. For partitions that have been solved, the corresponding network equipment configuration results are mapped back to the overall network configuration state to update the overall network corrected admittance matrix and the electrical background corresponding to the remaining partitions. Then, based on the updated overall network configuration state, the equivalence network and optimization sub-problems for subsequent partitions are reconstructed until all target renewable energy power plants meet the preset MRSCR requirements.

[0068] Therefore, this invention forms an accelerated solution method of "hierarchical partitioning—Schur network equivalence—partition optimization solution—network-wide state update". Compared with direct large-scale discrete optimization of the entire network, this method can significantly reduce the scale of a single solution while preserving the influence of electrical coupling across the entire network, improve the solution efficiency of optimization configuration problems for various types of network equipment, and enhance the engineering applicability of the obtained configuration scheme in large-scale new energy power grids.

[0069] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0070] This invention establishes a unified characterization framework for various types of grid-connected equipment, considering both short-circuit capacity support and overall economic cost, enabling unified modeling of different types of grid-connected equipment within the same optimization framework. By proposing an analytical constraint on the MRSCR (Mean Street Reduction and Reduction) considering the new steady-state voltage operating point of renewable energy power plants, it improves the accuracy and feasibility of embedding short-circuit ratio constraints into the optimization model. Furthermore, by constructing a hierarchical and partitioned system of "anchor point-root node-power plant cluster" and combining it with the Schur network equivalent method, it achieves dimensionality reduction and accelerated solution of large-scale renewable energy power grid configuration optimization problems, thereby ensuring both the voltage support capacity of renewable energy power plants and the economic efficiency of equipment configuration. Attached Figure Description

[0071] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0072] Figure 1 This is a schematic flowchart of a method for optimizing the configuration of multiple types of grid-building equipment for voltage support in large-scale new energy power grids, provided by an embodiment of the present invention. Detailed Implementation

[0073] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0074] The purpose of this invention is to provide an optimized configuration method for multiple types of grid-building equipment for voltage support in large-scale renewable energy power grids. This method aims to achieve unified modeling, optimized configuration, and efficient solution for multiple types of grid-building equipment in large-scale renewable energy power grid scenarios, ensuring sufficient voltage support capability for renewable energy power plants while also taking into account the economic efficiency of equipment configuration.

[0075] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0076] In one exemplary embodiment, such as Figure 1 As shown, this embodiment provides a method for optimizing the configuration of multiple types of network equipment for voltage support in large-scale new energy power grids. This method combines parametric characterization of multiple types of network equipment, analytical constraints of MRSCR, hierarchical partitioning system of "anchor point-root node-field group" and Schur network equivalent method to solve and output the optimization configuration scheme of multiple types of network equipment under large-scale new energy power grids.

[0077] Step 1: Input the power flow file and equipment parameters. The power flow file should include at least the power grid topology information, bus parameter information, branch parameter information, and renewable energy plant grid connection information. The equipment parameters should include at least the catalog parameters of various types of network equipment, actual installed capacity parameters, short-time overload capacity or equivalent short-circuit support coefficient parameters, comprehensive economic cost parameters, and candidate access location parameters. Among them, the candidate access location parameters are used to limit the configurable node range of various types of network equipment.

[0078] Step 2: Establish a parameterized characterization framework for various types of network equipment. Based on the input equipment catalog parameters, uniformly characterize the actual installed capacity, short-circuit capacity support capability, comprehensive economic cost, and accessible locations of different types of network equipment. Furthermore, uniformly convert the contribution of different types of network equipment to the system voltage support capability into short-circuit capacity support increments, thereby achieving a unified description of different types of network equipment under the same optimization framework.

[0079] Step 3: Establish the relationship between various types of network equipment and MRSCR improvement. Based on the network coupling relationship between renewable energy power plants, the change in network admittance caused by the access of network equipment is mapped to the change in voltage support strength of renewable energy power plants, and the effect of various types of network equipment configuration on MRSCR improvement is characterized accordingly.

[0080] Step 4: Establish analytical constraints for MRSCR considering the new steady-state voltage operating point. Combining the regional network admittance relationship and the network parameter changes caused by the access of network equipment, the short-circuit ratio constraints of multiple new energy power plants are transformed from the original impedance coupling expression into a constraint expression form suitable for optimization solution. In the modeling process, the influence of the difference in steady-state voltage operating points between different new energy power plants on the short-circuit ratio is preserved.

[0081] Step 5: Construct an optimized configuration model for multiple types of grid-connected equipment. Based on the above parametric characterization, short-circuit ratio improvement relationship, and analytical constraints, an optimized configuration model for multiple types of grid-connected equipment is constructed. The optimized configuration model aims to minimize the overall economic cost of multiple types of grid-connected equipment, while simultaneously considering the short-circuit ratio target requirements of new energy power plants, the configurable conditions of candidate access locations, and the discrete selection conditions for different types of grid-connected equipment. In this implementation, the multiple types of grid-connected equipment include at least one or more of synchronous condensers, grid-connected reactive power support devices, and grid-connected energy storage devices, as well as other grid-connected equipment capable of providing short-circuit capacity support or voltage support.

[0082] Step 6: Perform full network partitioning and construct Schur equivalent networks. Considering the large scale of the large-scale renewable energy power grid optimization problem, a hierarchical partitioning system of "anchor point-root node-power plant cluster" is constructed based on the electrical connection relationship between renewable energy power plants and the backbone network. The entire network is divided into multiple partition optimization units suitable for local solutions, and a corresponding Schur equivalent network is constructed for each partition to preserve the influence of the external network on the voltage support strength of the renewable energy power plants within the partition.

[0083] Step 7: Solve the partition model and back-substitute to update the entire network. For the current partition, construct a corresponding multi-type network equipment optimization configuration model and solve it using a solver to obtain the network equipment optimization configuration result for that partition. Then, substitute the current partition's optimization configuration result back to the entire network configuration state to update the network parameters and the equivalent networks corresponding to the remaining partitions, reflecting the impact of the previous partition optimization results on the voltage support conditions and network coupling relationships of subsequent partitions.

[0084] Step 8: Determine if all partitions have been optimized and output the results. If all partitions have been optimized, output the optimized configuration scheme for all network types of network devices and end the process. If there are still partitions that have not been optimized, move on to the next partition, rebuild the optimized configuration model for the corresponding partition, and continue to execute the solution and back-generation update process until all partitions are optimized. The final output of the network-wide optimized configuration scheme should include at least the network device type, access location, configuration capacity, and the corresponding network-wide MRSCR improvement results.

Claims

1. A method for optimizing the configuration of multiple types of grid-building equipment for voltage support in large-scale renewable energy power grids, characterized in that, include: Obtain network topology information, bus parameter information, new energy power station grid connection information, candidate network equipment access location information, and catalog parameter information of multiple types of network equipment for large-scale new energy power grids; Establish a parameterized characterization framework for multiple types of grid-connected equipment that considers short-circuit capacity support capability and comprehensive economic cost, and establish the relationship between the configuration of multiple types of grid-connected equipment and the improvement of short-circuit ratio of new energy multi-site power plants; Based on the new steady-state voltage operating point of new energy power stations, an analytical constraint on the short-circuit ratio of multiple new energy power stations is established, and an optimal configuration model for multiple types of network equipment is constructed accordingly. Based on the electrical connection relationship between new energy power plants and the backbone network in the power grid, a hierarchical zoning system of "anchor point-root node-power plant group" is constructed, and Schur network equivalence relationship is established for each zone; Based on the hierarchical zoning system, the Schur network equivalence relationship, and the multi-type network equipment optimization configuration model, the solution for each zone in the large-scale new energy power grid is accelerated, resulting in a multi-type network equipment optimization configuration scheme that meets the preset voltage support requirements of new energy power stations while taking into account the economic efficiency of equipment configuration.

2. The method for optimizing the configuration of multiple types of grid-building equipment for voltage support of large-scale new energy power grids according to claim 1, characterized in that, The multi-type grid-connected equipment includes at least one or more of synchronous condensers, grid-connected reactive power support devices, and grid-connected energy storage devices, as well as other grid-connected equipment capable of providing short-circuit capacity support or voltage support capabilities; in the parameterized characterization framework of the multi-type grid-connected equipment, the parameters of different types of grid-connected equipment include at least the actual installed capacity, equivalent short-circuit support capability, comprehensive economic cost, and set of accessible locations.

3. The method for optimizing the configuration of multiple types of grid-building equipment for voltage support of large-scale new energy power grids according to claim 2, characterized in that, The equivalent short-circuit support capability is characterized by the actual installed capacity and short-time overload capability or equivalent short-circuit support coefficient of the grid-connected equipment, and is used to uniformly describe the improvement effect of different types of grid-connected equipment on the short-circuit ratio of new energy multi-site power plants.

4. The method for optimizing the configuration of multiple types of grid-building equipment for voltage support of large-scale new energy power grids according to claim 1, characterized in that, The analytical constraint on the short-circuit ratio of multiple new energy power stations is established based on the relationship between the new steady-state voltage operating point of the new energy power station, the regional admittance matrix, and the admittance increment caused by the access of network equipment. It is used to characterize the voltage support strength constraint of multiple new energy power stations after coupling through the AC network.

5. The method for optimizing the configuration of multiple types of grid-building equipment for voltage support in large-scale new energy power grids according to claim 4, characterized in that, The multi-type network equipment optimization configuration model aims to minimize the overall economic cost of network equipment and includes constraints on the short-circuit ratio of multiple new energy power stations, constraints on the accessibility of candidate locations, and constraints on the selection of equipment types.

6. The method for optimizing the configuration of multiple types of grid-building equipment for voltage support of large-scale new energy power grids according to claim 1, characterized in that, The hierarchical zoning system of "anchor point-root node-field cluster" is constructed based on the grid connection location of new energy power plants, the hierarchical relationship of the grid backbone nodes, and the electrical connection relationship between power plants; the Schur network equivalent relationship is used to convert the electrical coupling influence of the external network on the reserved bus inside the zone into regional equivalent admittance and equivalent injection; the accelerated solution includes constructing optimization sub-problems for each zone based on the hierarchical zoning system, optimizing and solving each zone, and updating the overall network configuration status based on the zone solution results to obtain an optimized configuration scheme for multiple types of network equipment that meets the preset voltage support requirements of new energy power plants.

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