Method and system for determining the range of a site equivalent to a new energy power system

Abstract

The application discloses a method for determining the range of a station equivalent to a new energy power system, and discloses a system with the method for determining the range of the station equivalent to the new energy power system, wherein the method for determining the range of the station equivalent to the new energy power system is suitable for the research on problems such as power frequency related transient stability, short-circuit characteristics and overvoltage characteristics, and has certain compatibility for the analysis of problems such as sub- / super-synchronous oscillation close to the power frequency; on the other hand, the influence of the capacity of the new energy station is reflected, and the rule that the greater the capacity of the station is, the more significant the influence of the dynamic response of the station on other stations is is described; meanwhile, in the aspect of grouping, an improvement is made to the traditional K-means grouping method, so that the defect that one-dimensional data is difficult to accurately describe the electrical distance between multiple stations can be made up, and the grouping error is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of simplified equivalent modeling of power systems, in particular to a method and system for determining the range of stations for equivalent new energy power systems. BACKGROUND

[0002] Power system equivalence, also known as network reduction, is an analysis method that uses a smaller network to replace a larger network. For large interconnected power systems, it is often necessary to simplify the large power system and simplify the parts that do not need detailed analysis.

[0003] Among the domestic developed electromechanical transient equivalent calculation tools, the PSASP network equivalent calculation module and the PSD power grid data equivalent calculation tool use the conventional Ward static equivalent method and the EPRI E' equivalent method. These two calculation methods can adapt to different scale power network steady-state calculation and transient calculation scenarios. The equivalent results can be directly used for power flow calculation, short circuit calculation and various calculations based on power flow.

[0004] The conditions given by the static equivalent include the topology of the entire network and the element parameters, as well as the real-time power flow solution of the internal system and the boundary system. What needs to be solved is the equivalent network of the external system and the equivalent boundary injection current, so that the various analyses performed in the internal network after equivalent are the same as or very close to the results of the analyses performed in the real system without equivalent. The analysis mentioned here refers to the steady-state analysis of various disturbances in the internal network. It includes simplification processing of the network, units and loads. Power system static equivalence only involves steady-state power flow and does not involve transient process.

[0005] Currently, the domestic power grid equivalent calculation tool still relies on manual experience to set the equivalent range and equivalent conditions, and often can only propose differentiated determination methods according to specific problems, lacking corresponding means applicable to determining the equivalent station of new energy. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a method for determining the range of stations for equivalent new energy power systems, which can evaluate the coupling strength between new energy stations, and divide the stations into several groups according to the evaluation results, and then evaluate the coupling strength of the station groups to determine the station group that is closely coupled with the stations in the target area as the station that needs to be retained in the equivalent system.

[0007] The present application also proposes a system having the above-mentioned method for determining the range of stations for equivalent new energy power systems.

[0008] The method for determining the range of stations for equivalent new energy power systems according to the first aspect of the present application is characterized by comprising the following steps:

[0009] calculating the coupling coefficient between new energy stations based on the impedance of the power system;

[0010] grouping new energy stations according to the coupling coefficient between the stations, to obtain a plurality of groups;

[0011] calculating the group coupling strength between each of the groups, and determining the groups that need to be retained based on the group coupling strength.

[0012] The new energy power system equivalent station range determination method according to the embodiment of the application has at least the following beneficial effects: the application reflects the interaction caused by the impedance coupling of the power network, takes the power frequency impedance as the object, is suitable for the research on the transient stability, short-circuit characteristics, overvoltage characteristics and other problems related to the power frequency, and has a certain compatibility for the analysis of the near power frequency problems such as subsynchronous oscillation and ultrasy nchronous oscillation; on the other hand, the influence of the capacity of the new energy station is reflected, and the rule that the greater the capacity of the station, the more significant the influence of the dynamic response of the station on other stations is described; at the same time, in the grouping method, the traditional K-means grouping method is improved, the defect that the one-dimensional data cannot accurately describe the electrical distance between multiple stations is compensated, and the grouping error is reduced.

[0013] According to some embodiments of the application, the step of calculating the coupling coefficient between new energy stations based on the impedance of the power system comprises:

[0014] obtaining the original node impedance matrix of the power system at the power frequency under the premise of ignoring the new energy stations

[0015] based on the original node impedance matrix, in a simplified power system composed of only all new energy station grid nodes by ignoring other nodes, obtaining the reduced-order node impedance matrix Z of the simplified power system g , the element Z gij of the i-th row and j-th column is the mutual impedance amplitude between the i-th and j-th new energy station grid nodes, that is

[0016]

[0017] where n(i) and n(j) are the serial numbers of the i-th and j-th new energy station grid nodes in the original complete power grid, respectively;

[0018] calculating the coupling coefficient μ of the j-th station to the i-th station based on the capacity of the new energy station and the reduced-order node impedance matrix ij , that is

[0019] μ ij = Z gij S Gj .

[0020] According to some embodiments of the present application, the step of grouping the new energy power stations according to the coupling coefficients between the power stations to obtain a plurality of groups comprises:

[0021] The number of groups and the coupling coefficient threshold value are set according to experience;

[0022] Randomly select the same number of new energy power stations as the number of groups as the initial central power stations of the groups;

[0023] For any power station, according to the coupling coefficient of the power station with respect to the central power station of each group, the power station is placed in the group corresponding to the initial central power station with the largest coupling coefficient;

[0024] For the assigned groups, the average coupling coefficient of each power station in the group is calculated That is,

[0025]

[0026] Where A k represents the kth group to be calculated, M k is the number of power stations in the group, and the power station with the largest average coupling coefficient among the power stations is selected as the central power station of the group;

[0027] The steps of placing each power station in a group and reselecting the central power station are repeated until the members of each group no longer change, or a specified number of iterations is reached, to obtain the preliminary classified groups;

[0028] For each preliminary classified group, the minimum value of the coupling coefficients between the power stations in the group is calculated. If the number of groups does not exceed the number of new energy power stations, and there exists a group such that the minimum value of the coupling coefficients of the group is less than the coupling coefficient threshold value, then the number of groups is increased by one, and the above grouping process is repeated. Otherwise, the current classification result is taken as the classified groups.

[0029] According to some embodiments of the present application, the step of calculating the group coupling strength between each of the groups and determining the groups to be retained based on the group coupling strength comprises:

[0030] Obtain a preset average coupling coefficient threshold value between a group and a reference group;

[0031] Set the new energy power station with the largest capacity at the center position of the region to be analyzed as the reference power station, and let the group in which the reference power station is located be the reference group, which is retained in the equivalent system;

[0032] Calculate the average coupling coefficient λ k between other groups and the reference group, that is,

[0033]

[0034] Where k represents the group to be calculated, and its central station is j. k ;q represents the reference group, with its central station being j. q .

[0035] The judgment is made based on the set average coupling coefficient threshold value. If the average coupling coefficient of a group is greater than the average coupling coefficient threshold value, the group is retained; otherwise, it is discarded.

[0036] A system for determining the equivalent power station range of a new energy power system according to a second aspect embodiment of the present invention is characterized in that it comprises:

[0037] The coupling coefficient calculation module can calculate the coupling coefficient between new energy power plants based on the impedance of the power system.

[0038] The group iteration module can group the new energy power stations according to the coupling coefficient between the power stations to obtain several groups;

[0039] The group filtering module is capable of calculating the group coupling strength between each group and determining which groups need to be retained based on the group coupling strength.

[0040] According to some embodiments of the present invention, the coupling coefficient calculation module includes:

[0041] The original node impedance matrix calculation element can obtain the original node impedance matrix of the power system at power frequency without ignoring renewable energy power plants;

[0042] The reduced-order node impedance matrix calculation element can obtain the reduced-order node impedance matrix of the simplified power system, which ignores other nodes and consists only of all the grid-connected nodes of the new energy power plants.

[0043] The mutual impedance calculation element is capable of calculating the mutual impedance magnitude of each new energy node based on the original node impedance matrix and the reduced-order node impedance matrix.

[0044] The coupling coefficient calculation element can calculate the coupling coefficient between each power station based on the capacity of the new energy power station and the reduced-order node impedance matrix.

[0045] According to some embodiments of the present invention, the group iteration module includes:

[0046] The parameter setting element allows users to set the threshold values ​​for the number of clusters and the coupling coefficient based on experience.

[0047] The initial center selection element can randomly select a new energy power station with the same number of clusters as the initial center power station;

[0048] The group computing element can, for any given station, place it into the group corresponding to the initial central station with the largest coupling coefficient, based on the coupling coefficient between the central station and the station in each group.

[0049] The central station then selects components, which can calculate the average coupling coefficient of each station in the group after the allocation is completed, and select the station with the largest average coupling coefficient as the central station of the group.

[0050] The iterative element can perform the steps of placing each station into a group and reselecting the central station, repeating continuously until the members of each group no longer change, or until a specified number of iterations are reached, to obtain the preliminary classified groups;

[0051] The grouping and filtering element can calculate the minimum coupling coefficient between each station in each initially classified group. If the number of groups does not exceed the number of new energy stations, and there exists a group whose minimum coupling coefficient is less than the coupling coefficient threshold, then the number of groups is incremented by one, and the above grouping process is repeated. Otherwise, the current classification result is taken as the classified group.

[0052] According to some embodiments of the present invention, the group filtering module includes:

[0053] The average coupling coefficient threshold setting element can obtain a preset average coupling coefficient threshold value between the group and the reference group.

[0054] The reference group setting element can set the new energy power station with the largest capacity located in the center of the area to be analyzed as the reference power station, and make its group a reference group, which will be retained in the equivalent system.

[0055] The average coupling coefficient calculation element is capable of calculating the average coupling coefficient between other groups and the reference group;

[0056] The retention judgment element can make a judgment based on the set average coupling coefficient threshold value. If the average coupling coefficient of a certain group is greater than the average coupling coefficient threshold value, the group is retained; otherwise, it is discarded.

[0057] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0058] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0059] Figure 1This is a schematic diagram illustrating the steps of the method for determining the equivalent power station range of a new energy power system according to an embodiment of the present invention.

[0060] Figure 2 A structural block diagram of the system for determining the equivalent power station range of the new energy power system according to an embodiment of the present invention;

[0061] Figure 3 The diagram shows the topology of the computational system provided in this embodiment of the invention. Detailed Implementation

[0062] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0063] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0064] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0065] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0066] Reference Figure 1 The present invention provides a method for determining the equivalent power station range of a new energy power system, the method comprising at least the following steps:

[0067] Step S100: Calculate the coupling coefficient between new energy power stations based on the impedance of the power system.

[0068] Step S200: The new energy power stations are grouped according to the coupling coefficient between the power stations to obtain several groups.

[0069] Step S300: Calculate the group coupling strength between each group, and determine the groups that need to be retained based on the group coupling strength.

[0070] Specifically, to explain the process and calculation method of this application in more detail, the above steps will be described in detail. This method includes the following steps:

[0071] Step S100: Calculate the coupling coefficient between new energy power plants based on the impedance of the power system. Specifically, this includes:

[0072] Step S110: Obtain the original nodal impedance matrix of the power system at power frequency, ignoring renewable energy power plants.

[0073] The original nodal impedance matrix is ​​as follows:

[0074]

[0075] Where N is the total number of nodes in the power grid.

[0076] Step S120: Based on the original node impedance matrix, in a simplified power system that ignores other nodes and consists only of all renewable energy power plant grid-connected nodes, obtain the reduced-order node impedance matrix Z of the simplified power system. g .

[0077] The reduced-order nodal impedance matrix is ​​as follows:

[0078]

[0079] Where M represents the number of new energy power stations, and Z represents the number of power stations. gij Let be the mutual impedance amplitude between the grid-connected nodes of the i-th and j-th renewable energy power plants, i.e.:

[0080]

[0081] Where n(i) and n(j) are the serial numbers of the i-th and j-th renewable energy power station grid connection nodes in the original complete power grid, respectively, 1≤n(i), n(j)≤N, and if i=j, then Z gij This represents the self-impedance amplitude of the i-th grid-connected node of the renewable energy power station.

[0082] Step S130: Calculate the coupling coefficient between each power station based on the capacity of the new energy power station and the reduced-order node impedance matrix.

[0083] All the capacity of the new energy power stations are arranged into a diagonal matrix S. G ,Right now:

[0084]

[0085] The matrix μ of the coupling coefficients between each station is calculated according to the following formula:

[0086] μ = Z g S G (5)

[0087] Step S200: The new energy power stations are grouped according to the coupling coefficients between them, resulting in several groups. Specifically, this includes:

[0088] Step S210: Based on experience, set the number of clusters K and the coupling coefficient threshold value μ. minLim .

[0089] Step S220: Randomly select a new energy power station with the same number of clusters as the initial central power station.

[0090] Step S230: For any station i, based on the coupling coefficient μ between the station i and the central station c of each group... ic Place it into the group k corresponding to the initial central station with the largest coupling coefficient, that is, let i∈A k And complete the allocation of all stations.

[0091] Step S240: For the groups that have been allocated, calculate the average coupling coefficient of each station i in the group. The station with the highest average coupling coefficient among the stations was selected as the central station of the group.

[0092] The formula for the average coupling coefficient is:

[0093]

[0094] Where M k Let be the number of stations in the k-th group, and select . The station i corresponding to the maximum value is taken as the central station of the group, i.e., c = i.

[0095] Step S250: The process of placing each station into a group and reselecting the central station is repeated until the members of each group no longer change, or until a specified number of iterations is reached, to obtain the preliminary classified groups.

[0096] Step S260: For each initially classified group, calculate the minimum value of the coupling coefficient between each station within the group. If the number of groups does not exceed the number of new energy stations, and there exists a group such that the minimum value of the coupling coefficient of that group is less than the coupling coefficient threshold, then increment the number of groups by one and repeat the above grouping process. Otherwise, take the current classification result as the classified group.

[0097] For each group k, calculate the minimum value μ of the coupling coefficient between stations within the group. mink ,Right now:

[0098] μ mink = min{μ ji}, i, j ∈ A k , i ≠ j (7)

[0099] According to the set threshold value μ minLim Judge: If K < M and there is at least one group k that satisfies μ mink < μ minLim , then let the number of clusters K = K + 1, and repeat the above steps S220 to S250. Otherwise, end the calculation and output the number of clusters K, the serial numbers of all stations in each group, and the serial number of the central station.

[0100] Step S300: Calculate the group coupling strength between each of the said groups, and determine the groups to be retained based on the group coupling strength. Specifically, it includes:

[0101] Step S310: Set the average coupling coefficient threshold value λ between the group and the reference group according to experience Lim .

[0102] Step S320: Set the new energy station p with the largest capacity at the central position of the area to be analyzed as the reference station, and let the group q where it is located be the reference group (the central station is j q ), and retain it in the equivalent system.

[0103] Step S330: Calculate the average coupling coefficient λ between other groups k (k ≠ q, the central station is j k ) and the reference group q k .

[0104] The specific formula is:

[0105]

[0106] Step S340: Make a judgment according to the set average coupling coefficient threshold value λ Lim . If the average coupling coefficient of a certain group k is greater than the average coupling coefficient threshold value, that is, λ k ≥ λ Lim , then retain this group, otherwise discard it.

[0107] Furthermore, an embodiment of another aspect of the present application provides a system for determining the station range of equivalent of a new energy power system, as Figure 2 shown. This system 20 includes:

[0108] A coupling coefficient calculation module 201, which can calculate the coupling coefficient between new energy stations based on the impedance of the power system;

[0109] The group iteration module 202 can group the new energy power stations according to the coupling coefficient between the power stations to obtain several groups;

[0110] The group filtering module 203 is capable of calculating the group coupling strength between each group and determining the groups to be retained based on the group coupling strength.

[0111] The coupling coefficient between new energy power stations proposed in the embodiments of this application reflects, on the one hand, the interaction effect brought about by the impedance coupling of the power network. Taking power frequency impedance as the object, it is applicable to the study of power frequency-related transient stability, short-circuit characteristics, overvoltage characteristics and other problems, and also has a certain compatibility with the analysis of sub / supersynchronous oscillations and other problems close to power frequency. On the other hand, it reflects the impact of the capacity of new energy power stations, describing the law that the larger the capacity of the power station, the more significant its dynamic response is to other power stations.

[0112] Regarding station clustering, this invention shares similarities in principle with the traditional K-means clustering method, but also has differences. The main differences are: the traditional K-means clustering method clusters 1-dimensional data, while this invention clusters high-dimensional matrix data; the traditional K-means clustering method uses geometric numerical calculations for distance calculation and centroid acquisition, while this invention describes distance as the coupling coefficient between stations, and the principle for acquiring centroids is to select the station with the strongest overall coupling to all stations; the traditional K-means clustering method, relying solely on 1-dimensional data, struggles to accurately describe the electrical distance between multiple stations, leading to significant clustering errors. For example, it is often difficult to accurately distinguish whether different stations at a distance belong to different groups. This invention avoids these drawbacks.

[0113] In determining the scope of new energy power stations that should be retained in the system, this invention proposes a feasible automatic calculation method by analyzing the coupling degree between each power station group and the reference power station group, avoiding reliance on engineering experience and enabling rapid and effective execution through a program.

[0114] Furthermore, the coupling coefficient calculation module 201 includes:

[0115] The original node impedance matrix calculation element can obtain the original node impedance matrix of the power system at power frequency without ignoring renewable energy power plants;

[0116] The reduced-order node impedance matrix calculation element can obtain the reduced-order node impedance matrix of the simplified power system based on the original node impedance matrix, ignoring other nodes and consisting only of all new energy power plant grid-connected nodes in the simplified power system.

[0117] The coupling coefficient calculation element can calculate the coupling coefficient between each power station based on the capacity of the new energy power station and the reduced-order node impedance matrix.

[0118] Further, the group iteration module 202 includes:

[0119] The parameter setting element allows users to set the threshold values ​​for the number of clusters and the coupling coefficient based on experience.

[0120] The initial center selection element can randomly select a new energy power station with the same number of clusters as the initial center power station;

[0121] The group computing element can, for any given station, place it into the group corresponding to the initial central station with the largest coupling coefficient, based on the coupling coefficient between the central station and the station in each group.

[0122] The central station then selects components, which can calculate the average coupling coefficient of each station in the group after the allocation is completed, and select the station with the largest average coupling coefficient as the central station of the group.

[0123] The iterative element can perform the steps of placing each station into a group and reselecting the central station, repeating continuously until the members of each group no longer change, or until a specified number of iterations are reached, to obtain the preliminary classified groups;

[0124] The grouping and filtering element can calculate the minimum coupling coefficient between each station in each initially classified group. If the number of groups does not exceed the number of new energy stations, and there exists a group whose minimum coupling coefficient is less than the coupling coefficient threshold, then the number of groups is incremented by one, and the above grouping process is repeated. Otherwise, the current classification result is taken as the classified group.

[0125] Furthermore, the group filtering module 203 includes:

[0126] The average coupling coefficient threshold setting element can set the average coupling coefficient threshold between the group and the reference group based on experience.

[0127] The reference group setting element can set the new energy power station with the largest capacity located in the center of the area to be analyzed as the reference power station, and make its group a reference group, which will be retained in the equivalent system.

[0128] The average coupling coefficient calculation element is capable of calculating the average coupling coefficient between other groups and the reference group;

[0129] The retention judgment element can make a judgment based on the set average coupling coefficient threshold value. If the average coupling coefficient of a certain group is greater than the average coupling coefficient threshold value, the group is retained; otherwise, it is discarded.

[0130] An embodiment of the third aspect of the present invention provides a computational example based on the above method.

[0131] The example uses the equivalent system of a real domestic power grid, such as... Figure 3 As shown, the system consists of a 500kV main grid (green part) and a local 220kV system (black part). The 220kV busbars of substations A, B, C, D and E in the figure are connected to the wind farms, and the rated capacity of each wind farm is 400MW.

[0132] The following steps describe the process of obtaining the equivalent range of new energy power stations, including: calculating the coupling coefficient between new energy power stations; grouping new energy power stations according to their coupling strength with selected power stations; calculating the coupling strength between power station groups and determining which power station groups need to be retained. Per-unit system is used in the calculations, with a system base capacity of 1000 MVA and a base voltage of the rated voltage at each voltage level node.

[0133] 1. Calculate the coupling coefficient between new energy power stations

[0134] Ignoring renewable energy power plants, the node impedance matrix of the power network is obtained at the power frequency, and then the node impedance magnitude matrix Zg of the simplified power network composed of all renewable energy power plant grid-connected nodes is obtained, with order N=6. The data of each row and column are shown in Table 1.

[0135] Table 1. Calculation results of the simplified power network node impedance magnitude matrix Zg

[0136] Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 1 0.706 0.080 0.222 0.244 0.245 0.245 Site 2 0.080 0.900 0.080 0.082 0.082 0.082 Site 3 0.222 0.080 0.414 0.227 0.228 0.228 Site 4 0.244 0.082 0.227 1.143 0.801 0.801 Site 5 0.245 0.082 0.228 0.801 1.660 1.304 Site 6 0.245 0.082 0.228 0.801 1.304 1.560

[0137] All the new energy power plant capacities are arranged into a diagonal matrix SG, and the diagonal elements are the capacities of each wind farm divided by the system baseline capacity, with a value of 400 / 1000 = 0.4.

[0138] The coupling coefficient matrix μ between each station is calculated based on μ = ZgSG, and the data of each row and column are shown in Table 2.

[0139] Table 2 shows the calculation results of the coupling coefficient matrix μ between stations.

[0140] Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 1 0.282 0.032 0.089 0.098 0.098 0.098 Site 2 0.032 0.360 0.032 0.033 0.033 0.033 Site 3 0.089 0.032 0.165 0.091 0.091 0.091 Site 4 0.098 0.033 0.091 0.457 0.321 0.320 Site 5 0.098 0.033 0.091 0.321 0.664 0.522 Site 6 0.098 0.033 0.091 0.320 0.522 0.624

[0141] With the cluster number K=3, the intra-cluster coupling coefficient threshold value μminLim=0.2, and the average coupling coefficient threshold value λLim between the cluster and the reference cluster=0.1, the clustering process described in this invention is used to iteratively perform steps such as site cluster allocation, cluster center site selection, and evaluation of the minimum intra-cluster coupling coefficient. The clustering results for two steps (K=3 and K=4) are shown in Table 3.

[0142] Table 3. Site clustering results for different cluster sizes in the clustering process.

[0143]

[0144] Wind farm 6, located at the end of the power grid to be analyzed, is set as the reference site, and its group {4,5,6} is the reference group and is retained in the equivalent system. By calculating the average coupling coefficient between other groups and the reference group and comparing it with the set threshold value λLim = 0.1, it is determined whether other groups are retained in the equivalent system. The results are shown in Table 3.

[0145] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; 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.

[0146] Another embodiment of this application provides a terminal, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for determining the equivalent range of a new energy power system.

[0147] Specifically, the processor can be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements computational functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0148] Specifically, the processor connects to the memory via a bus, which may include a path for transmitting information. The bus can be a PCI bus or an EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc.

[0149] The memory may be ROM or other types of static storage devices that can store static information and instructions, RAM or other types of dynamic storage devices that can store information and instructions, or EEPROM, CD-ROM or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto.

[0150] Optionally, the memory stores the code of the computer program that executes the scheme of this application, and the execution is controlled by the processor. The processor executes the application code stored in the memory to implement... Figure 2 The embodiment shown provides the functionality of a system for determining the equivalent site range of a new energy power system.

[0151] Another embodiment of this application provides a computer-readable storage medium storing computer-executable instructions for performing the above-described... Figure 1 The method for determining the equivalent site range of the new energy power system is shown.

[0152] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; 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.

[0153] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0154] The above is a detailed description of the preferred embodiments of this application. However, this application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for determining the equivalent power station range of a new energy power system, characterized in that, Includes the following steps: Calculation of coupling coefficients between new energy power plants based on power system impedance; including: Obtain the original nodal impedance matrix of the power system at power frequency, ignoring renewable energy power plants. Based on the original node impedance matrix, in a simplified power system that ignores other nodes and consists only of all renewable energy power plant grid-connected nodes, the reduced-order node impedance matrix Z of the simplified power system is obtained. g Its element Z in the i-th row and j-th column gij Let be the mutual impedance amplitude between the grid-connected nodes of the i-th and j-th renewable energy power plants, i.e. Where n(i) and n(j) are the serial numbers of the i-th and j-th renewable energy power station grid connection nodes in the original complete power grid, respectively; The coupling coefficient μ of the j-th power station to the i-th power station is calculated based on the capacity of the new energy power station and the reduced-order node impedance matrix. ij ,Right now μ ij =Z gij S Gj 。 Where, μ ij S is the coupling coefficient between the j-th station and the i-th station. Gj This represents the capacity of the j-th renewable energy power station; The new energy power stations are grouped according to the coupling coefficient between them, resulting in several groups; Calculate the group coupling strength between each group, and determine the groups that need to be retained based on the group coupling strength.

2. The method according to claim 1, characterized in that, The step of grouping the new energy power stations according to the coupling coefficient between the power stations to obtain several groups includes: The threshold values ​​for the number of clusters and the coupling coefficient are set based on experience; Randomly select new energy power stations with the same number of clusters as the initial central power stations for each cluster; For any given station, based on the coupling coefficient between the central station of each group and that station, it is placed into the group corresponding to the initial central station with the largest coupling coefficient; For the assigned groups, calculate the average coupling coefficient for each station in the group. Right now Where A k M represents the k-th group to be calculated. k The number of stations in the group is given, and the station with the highest average coupling coefficient among the stations is selected as the central station of the group. The process of placing each site into a group and reselecting the central site is repeated until the members of each group no longer change, or until a specified number of iterations are reached, resulting in a preliminary classification of the groups. For each initially classified group, calculate the minimum coupling coefficient between each station within the group. If the number of groups does not exceed the number of new energy stations, and there exists a group whose minimum coupling coefficient is less than the coupling coefficient threshold, then increment the group number by one and repeat the above grouping process. Otherwise, take the current classification result as the classified group.

3. The method according to claim 1, characterized in that, The step of calculating the group coupling strength between each of the groups and determining which groups need to be retained based on the group coupling strength includes: Obtain the preset average coupling coefficient threshold value between the group and the reference group; The new energy power station located at the center of the region to be analyzed and having the largest capacity is set as the reference power station, and its group is set as the reference group, which is retained in the equivalence system. Calculate the average coupling coefficient λ between other groups and the reference group. k ,Right now Where k represents the group to be calculated, and its central station is j. k , For the central station j k The coupling coefficient; q represents the reference group, whose central station is j. q , For the central station j q Coupling coefficient The judgment is made based on the set average coupling coefficient threshold value. If the average coupling coefficient of a group is greater than the average coupling coefficient threshold value, the group is retained; otherwise, it is discarded.

4. A system for determining the equivalent range of power stations in a new energy power system, characterized in that, include: The coupling coefficient calculation module is capable of calculating the coupling coefficient between renewable energy power plants based on the impedance of the power system. It includes: a raw node impedance matrix calculation element, capable of obtaining the raw node impedance matrix of the power system at power frequency, ignoring renewable energy power plants; a reduced-order node impedance matrix calculation element, capable of obtaining the reduced-order node impedance matrix of the simplified power system, ignoring other nodes and consisting only of all renewable energy power plant grid-connected nodes, based on the raw node impedance matrix; and a coupling coefficient calculation element, capable of calculating the coupling coefficient between each power plant based on the capacity of the renewable energy power plant and the reduced-order node impedance matrix. The group iteration module can group the new energy power stations according to the coupling coefficient between the power stations to obtain several groups; The group filtering module is capable of calculating the group coupling strength between each group and determining which groups need to be retained based on the group coupling strength.

5. The system according to claim 4, characterized in that, The group iteration module includes: The parameter setting element allows users to set the threshold values ​​for the number of clusters and the coupling coefficient based on experience. The initial center selection element can randomly select a new energy power station with the same number of clusters as the initial center power station; The group computing element can, for any given station, place it into the group corresponding to the initial central station with the largest coupling coefficient, based on the coupling coefficient between the central station and the station in each group. The central station then selects components, which can calculate the average coupling coefficient of each station in the group after the allocation is completed, and select the station with the largest average coupling coefficient as the central station of the group. The iterative element can perform the steps of placing each station into a group and reselecting the central station, repeating continuously until the members of each group no longer change, or until a specified number of iterations are reached, to obtain the preliminary classified groups; The grouping and filtering element can calculate the minimum coupling coefficient between each station in each initially classified group. If the number of groups does not exceed the number of new energy stations, and there exists a group whose minimum coupling coefficient is less than the coupling coefficient threshold, then the number of groups is incremented by one, and the above grouping process is repeated. Otherwise, the current classification result is taken as the classified group.

6. The system according to claim 4, characterized in that, The group filtering module includes: The average coupling coefficient threshold setting element can obtain a preset average coupling coefficient threshold value between the group and the reference group. The reference group setting element can set the new energy power station with the largest capacity located in the center of the area to be analyzed as the reference power station, and make its group a reference group, which will be retained in the equivalent system. The average coupling coefficient calculation element is capable of calculating the average coupling coefficient between other groups and the reference group; The retention judgment element can make a judgment based on the set average coupling coefficient threshold value. If the average coupling coefficient of a certain group is greater than the average coupling coefficient threshold value, the group is retained; otherwise, it is discarded.

7. A terminal, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the method of any one of claims 1 to 3.

8. A computer-readable storage medium storing computer-executable instructions for performing the method of any one of claims 1 to 3.

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