Analysis method of multistage section coupling rule under static voltage stability and related device

Abstract

The invention discloses an analysis method for a multistage section coupling rule under static voltage stability and a related device, and relates to the technical field of power system analysis, and the method comprises the steps: obtaining a topological structure of a new energy delivery system and the output of each station, and carrying out the disassembly and decoupling of reactance into independent branches; and the independent branch comprises a field station, a reactor and a power grid access point. And calculating the static voltage stability limit of each branch, determining a system section power expression, and performing adjustment. According to the sequence of reaching the static voltage stability limit by the new energy station in the new energy delivery system, the power expression of each section and the output of each new energy station at the moment, determining the limit formula of each section; and determining a multi-stage section coupling rule change curve of the section limit according to the section limit formula of each stage. The method can effectively evaluate and predict the coupling rule of the multi-stage section under the static voltage stability condition.

Description

Technical Field

[0001] The present application relates to the technical field of power system analysis, and in particular to a method for analyzing the coupling law of multi-stage sections under static voltage stability and a related device. Background Art

[0002] The new energy transmission system is a wind farm group composed of a large number of wind farms. The wind farm group is transmitted to the main grid through transmission channels of different voltage levels, and then transmitted to the load center for consumption. For large-scale wind farm groups, their transmission channels are often composed of multi-level sections, and many different wind farms are connected to each section. Due to the limitations of the transmission section limit, the wind farms under the channel often have long-term power outages and serious wind abandonment. With the gradual expansion of the scale of cross-regional interconnection of power grids, the limits of multi-level sections have interactive effects and tight coupling phenomena. At present, there is a lack of analysis on the coupling law of multi-level sections under the constraints of static voltage stability. Summary of the invention

[0003] The purpose of this application is to provide an analysis method and related device for the coupling law of multi-level sections under static voltage stability, which can effectively evaluate and predict the coupling law of multi-level sections under static voltage stability conditions.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] In a first aspect, the present application provides a method for analyzing the coupling law of multi-stage sections under static voltage stability, including:

[0006] The topological structure of the new energy transmission system and the output of each new energy station in the new energy transmission system are obtained; the topological structure is a multi-stage series section topological structure.

[0007] By using the reactance splitting method, the topological structure of the new energy transmission system is decoupled to obtain a plurality of independent branches; the independent branches include the new energy station, the split reactance and the grid access point.

[0008] According to the output of the new energy station in each independent branch, the size of the reactance after splitting and the voltage at the grid access point, the static voltage stability limit of each independent branch is calculated respectively.

[0009] According to the output of each new energy station, the power expression of each section of the new energy transmission system is determined.

[0010] The output of the renewable energy transmission system is adjusted until any renewable energy station reaches the static voltage stability limit.

[0011] According to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expression of each section and the output of each new energy station at this moment, the limit formulas for each level of sections are determined.

[0012] According to the limit formulas of each level of sections, the multi-level section coupling law change curve of section limit is determined.

[0013] Optionally, according to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expressions of each section and the output of each new energy station at this moment, the limit formulas of each level of sections are determined, specifically including:

[0014] When the new energy station farthest from the grid access point in the new energy transmission system reaches the static voltage stability limit first, the first formula for the limits of each level of sections is determined based on the power expression of each section and the output of each new energy station at this moment.

[0015] When the new energy station closest to the grid access point in the new energy transmission system reaches the static voltage stability limit first, the second formula for the limits of each level of sections is determined based on the power expression of each section and the output of each new energy station at this moment.

[0016] When the non-farthest and non-closest renewable energy stations in the renewable energy transmission system reach the static voltage stability limit first, the third formula for the limits of each level of sections is determined based on the power expression of each section and the output of each renewable energy station at this moment.

[0017] Optionally, the multi-stage series section topology structure includes the output of several new energy stations, the voltage of the grid access point, the access reactance of each new energy station, the transmission reactance collected by different new energy stations, and the section distribution.

[0018] Optionally, in the new energy transmission system, when there are three new energy stations, and the distances between the new energy stations A, B, and C and the grid access point decrease in sequence, the power expression of each section of the new energy delivery system is specifically:

[0019]

[0020] Among them, P A , P B , P C is the output of new energy stations A, B, and C; P1, P2, and P3 are the power of the first, second, and third level sections.

[0021] Optionally, the expression of the reactance after separation in the independent branch is specifically:

[0022]

[0023] Among them, XCD1 , X 11 , X 12 They are respectively new energy station C, new energy station B and new energy station A, which are the reactances after splitting, and X BC The output reactance of the new energy station B and the new energy station C, X CD It is the sending reactance collected by the new energy station C.

[0024] Optionally, according to the output of the new energy station in each independent branch, the size of the split reactance and the voltage at the grid access point, the static voltage stability limit of each independent branch is calculated respectively, specifically:

[0025] According to the formula Calculate the static voltage stability limits of the independent branches of new energy station A, new energy station B and new energy station C.

[0026] Among them, U is the voltage at the grid access point, X A , X B , X C are the access reactances of new energy stations A, B, and C, respectively, and X AB It is the output reactance collected by new energy station A and new energy station B.

[0027] Optionally, the first formula of the section limit at each level is specifically:

[0028]

[0029] The second formula of the section limit at each level is specifically:

[0030]

[0031] The third formula of the section limit at each level is specifically:

[0032]

[0033] Where k1=k+1, k is the step length; P A0 , P B0 , P C0 It is the initial output of new energy stations A, B, and C.

[0034] In a second aspect, the present application provides an analysis system for multi-level cross-section coupling law under static voltage stability, including:

[0035] The information acquisition module is used to obtain the topological structure of the new energy transmission system and the output of each new energy station in the new energy transmission system; the topological structure is a multi-stage series section topological structure.

[0036] The decoupling module is used to decouple the topological structure of the renewable energy transmission system by means of reactance splitting to obtain a plurality of independent branches; the independent branches include renewable energy stations, split reactances and grid access points.

[0037] The static stability limit calculation module is used to calculate the static voltage stability limit of each independent branch according to the output of the new energy station in each independent branch, the size of the split reactance and the voltage of the grid access point.

[0038] The cross-sectional power expression calculation module is used to determine the cross-sectional power expressions of the renewable energy transmission system according to the output of each renewable energy station.

[0039] The output regulation module is used to regulate the output of the renewable energy transmission system until any renewable energy station reaches the static voltage stability limit.

[0040] The formula calculation module is used to determine the limit formulas of each level of sections according to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expression of each section and the output of each new energy station at this moment.

[0041] The multi-stage section coupling law variation curve construction module is used to determine the multi-stage section coupling law variation curve of the section limit according to the section limit formulas of each level.

[0042] In a third aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-mentioned methods for analyzing the coupling law of multi-level sections under static voltage stability.

[0043] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-mentioned methods for analyzing the coupling law of multi-level sections under static voltage stability.

[0044] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0045] The present application provides an analysis method and related device for the coupling law of multi-level sections under static voltage stability, the method comprising: obtaining the network structure of a new energy transmission system and the power generation conditions of each new energy power station therein; the network structure is in the form of a multi-level series section; the network structure of the new energy transmission system is decoupled by reactance splitting technology, thereby obtaining a number of independent branches; these independent branches include new energy power stations, decomposed reactances and grid access points; according to the power generation conditions of the new energy power stations in each independent branch, the decomposed reactance values ​​and the voltage of the grid access point, the static voltage stability limit of each independent branch is calculated respectively; according to the power generation conditions of each new energy power station, the power expression of each section of the new energy transmission system is determined; the power generation of the new energy transmission system is adjusted until any new energy power station reaches the static voltage stability limit; when the new energy power station at the farthest end from the grid access point in the new energy transmission system When the power station first reaches the static voltage stability limit, the first formula of each section limit is determined according to the power expression of each section and the power generation situation of each new energy power station at this time; when the new energy power station closest to the grid access point in the new energy transmission system first reaches the static voltage stability limit, the second formula of each section limit is determined according to the power expression of each section and the power generation situation of each new energy power station at this time; when the new energy power station that is neither the farthest end nor the closest end in the new energy transmission system first reaches the static voltage stability limit, the third formula of each section limit is determined according to the power expression of each section and the power generation situation of each new energy power station at this time; according to the first formula of each section limit, the second formula of each section limit and the third formula of each section limit, the first multi-level section coupling law change curve, the second multi-level section coupling law change curve and the third multi-level section coupling law change curve of the section limit are respectively determined. Through the method proposed in this application, the network structure of the new energy transmission system is decoupled, the power-coupled lines are split into independent transmission lines, and then the influence of the initial power generation of the wind farm on the cross-sectional limit is analyzed and discussed according to which wind farm reaches the limit first. Then, the wind farm that reaches the limit first as the initial power generation of the wind farm increases is analyzed, and the change curve of the cross-sectional limit is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A flowchart of a method for analyzing the coupling law of multi-stage sections under static voltage stability provided in one embodiment of the present application.

[0048] Figure 2 A schematic diagram of a multi-stage series cross-sectional topological structure of a new energy transmission system provided in one embodiment of the present application.

[0049] Figure 3 A schematic diagram of the topological structure after reactance splitting provided in one embodiment of the present application.

[0050] Figure 4 A schematic diagram of the coupling law between the output of wind farm A and the cross-sectional limit provided in one embodiment of the present application.

[0051] Figure 5 A schematic diagram of the coupling law between the output of wind farm B and the cross-sectional limit provided in one embodiment of the present application.

[0052] Figure 6 This is a structural diagram of a simulation model of a new energy transmission system in a certain province provided in one embodiment of the present application.

[0053] Figure 7 This is a graph showing the changing trend of the cross-sectional limit as the initial output of wind farm A increases, provided in one embodiment of the present application.

[0054] Figure 8 This is a graph showing the changing trend of the cross-sectional limit as the initial output of wind farm B increases, provided in one embodiment of the present application.

[0055] Fig. 9 A schematic diagram of functional modules of a system for analyzing multi-stage cross-section coupling laws under static voltage stability provided in one embodiment of the present application.

[0056] Fig.10 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0058] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0059] Embodiment 1

[0060] like Figure 1 As shown, this embodiment provides a method for analyzing the coupling law of multi-stage sections under static voltage stability, including:

[0061] Step 101: Obtain the topological structure of the new energy transmission system and the output of each new energy station in the new energy transmission system; the topological structure is a multi-stage series section topological structure.

[0062] Step 102: Decoupling the topological structure of the new energy transmission system by means of reactance splitting to obtain a plurality of independent branches; the independent branches include the new energy station, the split reactance and the grid access point.

[0063] Step 103: Calculate the static voltage stability limit of each independent branch according to the output of the new energy station in each independent branch, the size of the split reactance, and the voltage of the grid access point.

[0064] Step 104: Determine the power expression of each section of the new energy transmission system according to the output of each new energy station.

[0065] Step 105: Adjust the output of the renewable energy transmission system until any renewable energy station reaches the static voltage stability limit.

[0066] Step 106: Determine the limit formulas for each level of sections according to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expressions of each section, and the output of each new energy station at this moment.

[0067] Step 107: According to the section limit formulas at each level, determine the multi-level section coupling law variation curve of the section limit.

[0068] In some embodiments, when executing step 101, the specific steps may be as follows:

[0069] A multi-stage series cross-sectional topological structure of a new energy transmission system is obtained, wherein the number of new energy stations in the new energy transmission system is at least three. Figure 2 As shown, the multi-stage series section topology structure includes the output of several new energy stations, the voltage of the grid access point, the access reactance of each new energy station, the transmission reactance collected by different new energy stations, and the section distribution.

[0070] Specifically, P A , P B , P C is the output of new energy stations A, B, and C, U is the voltage at the grid access point, and X A , X B , X C is the access reactance of stations A, B, and C, X AB , X BC , X CD To collect and send reactances at different stations, the section is set on the station collection and sending lines.

[0071] In some embodiments, when executing step 102, the specific steps may be as follows:

[0072] In the new energy transmission system, when there are three new energy stations, and the distances between the new energy stations A, B, and C and the grid access point decrease in sequence, Figure 2 The power of each section represented by the output of the new energy station can be obtained as shown in formula (1).

[0073]

[0074] Among them, P A , P B , P C is the output of new energy stations A, B, and C; P1, P2, and P3 are the power of the first, second, and third level sections.

[0075] Among them, the output power of stations A and B is X BC The output power of stations A, B, and C is at X CD Coupling at X BC , X CD By performing reactance splitting at each location, the power coupled system can be decoupled as follows: Figure 3 The system is shown as three independent branches, where X CD1 , X 11 , X 12 is the reactance after splitting.

[0076] Since the voltage across the reactance needs to remain unchanged before and after the split, the power flowing through the reactance before and after the split needs to satisfy the power transfer expression and the reactance after the split is equal to the reactance before the split. Figure 2 , 3 The reactance after decomposition can be obtained as shown in formula (2).

[0077]

[0078] Among them, X CD1 , X 11 , X 12 They are respectively new energy station C, new energy station B and new energy station A, which are the reactances after splitting, and X BC The output reactance of the new energy station B and the new energy station C, X CD It is the sending reactance collected by the new energy station C.

[0079] In some embodiments, when executing step 103, the specific steps may be as follows:

[0080] According to the output of the new energy station in each independent branch, the size of the split reactance and the voltage at the grid access point, the static voltage stability limit of each independent branch is calculated separately, which can be specifically as follows:

[0081] Among them, the static voltage stability limit of a single-machine infinite system connected to the power grid is shown in formula (3):

[0082]

[0083] Where U is the voltage at the grid access point, and X is the reactance of the grid. Figure 3 The static voltage stability limits of the three independent branches are shown in formula (4):

[0084]

[0085] Among them, U is the voltage at the grid access point, X A , X B , X C are the access reactances of new energy stations A, B, and C, respectively, and X AB It is the output reactance collected by new energy station A and new energy station B.

[0086] In some embodiments, when executing steps 105-107, the specific steps may be as follows:

[0087] For a multi-node transmission system, when a node reaches the static stability limit of that point first, the static stability limit of the entire transmission system is determined. To analyze the coupling law of the initial output of a new energy station to the cross-sectional limit, it is necessary to analyze the new energy station that reaches the limit first.

[0088] According to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expression of each section and the output of each new energy station at this moment, the limit formulas for each level of sections are determined.

[0089] According to the limit formulas of each level of sections, the multi-level section coupling law change curve of section limit is determined.

[0090] Specifically, when the new energy station farthest from the grid access point in the new energy transmission system reaches the static voltage stability limit first, the first formula for the limits of each level of sections is determined based on the power expression of each section and the output of each new energy station at this moment.

[0091] When the new energy station closest to the grid access point in the new energy transmission system reaches the static voltage stability limit first, the second formula for the limits of each level of sections is determined based on the power expression of each section and the output of each new energy station at this moment.

[0092] When the non-farthest and non-closest renewable energy stations in the renewable energy transmission system reach the static voltage stability limit first, the third formula for the limits of each level of sections is determined based on the power expression of each section and the output of each renewable energy station at this moment.

[0093] According to the first formula of each level of section limit, the second formula of each level of section limit and the third formula of each level of section limit, the first multi-level section coupling law change curve, the second multi-level section coupling law change curve and the third multi-level section coupling law change curve of section limit are respectively determined.

[0094] For example, suppose that the new energy station A reaches the limit first, then the output of each new energy station is P Amax =k1P A0 , P B =k1P B0 , P C =k1P C0 Among them, P A0 , P B0 , P C0 is the initial output of the new energy stations A, B, and C, k1=k+1, k is the step length. From formula (4), we can get k1 when the new energy station A reaches the limit first, as shown in formula (5):

[0095]

[0096] From equation (1) and equation (5), we can get that the cross-section limits of each level are as shown in equation (6).

[0097]

[0098] From formula (6), it can be analyzed that when the new energy station A reaches the limit first, as the initial output of the new energy station A P A0 The first-level section limit gradually decreases, and the third-level section limit gradually increases. The change trend of the second-level section limit and the reactance X A +X AB and X CD The size is related to the actual new energy transmission system analysis, and it can be obtained that (X A +X AB )>X CD , so the secondary section limit increases with P A0 As the initial output of the new energy station B P B0 As the pressure increases, the first and second level section limits gradually increase, while the third level section limit gradually decreases.

[0099] Assuming that the new energy stations B and C reach their limits first, the limits of each level of sections under the corresponding conditions can be obtained as shown in equations (7) and (8):

[0100]

[0101] From formula (7), it can be analyzed that when the new energy station B reaches the limit first, as the initial output of the new energy station A P A0 As the initial output of the new energy station B increases, the limits of the first, second and third level sections gradually increase. B0 As the pressure increases, the first and third level section limits gradually decrease, while the second level section limit gradually increases.

[0102] From formula (8), it can be analyzed that when the new energy station C reaches the limit first, as the initial output of the new energy station A P A0 As the initial output of the new energy station B increases, the limits of the first, second and third level sections gradually increase. B0 As the pressure increases, the first and second level section limits gradually increase, while the third level section limit gradually decreases.

[0103] Therefore, as the initial output of the new energy station A P A0 No matter which new energy station reaches the limit first, the limit of the third section always increases. The power limit of the first and second sections decreases when the new energy station A reaches the limit first, and increases when the new energy station BC reaches the limit first. B0 The power limit of the second-level section always increases, and the power limit of the third-level section always decreases. The power limit of the first-level section increases when the new energy station AC reaches the limit first, and decreases when the new energy station B reaches the limit first, as shown in formula (9).

[0104]

[0105] Assuming that the output is evenly distributed, it means that the initial output of each new energy station is proportional to its rated capacity. When the output is evenly distributed and the output growth mode of each new energy station is even growth, each new energy station can reach the limit at the same time. As the initial output of new energy stations A and B increases, the new energy station that reaches the limit first is shown in formula (10).

[0106]

[0107] Among them, P A0均匀 , P B0均匀 It is the initial output of new energy stations A and B when the output is evenly distributed.

[0108] From equations (9) and (10), we can get that as the initial output of the new energy station A increases, A0 Increases, the first and second level section limits increase first and then decrease, and the third level section limit increases gradually, such as Figure 4 shown.

[0109] As the initial output of the new energy station B P B0Increases, the first-level section limit increases first and then decreases, the second-level section limit gradually increases, and the third-level section limit gradually decreases, such as Figure 5 shown.

[0110] Therefore, the present application assumes that the section closer to the grid side is the upper section, and the section far from the grid side is the lower section. Figure 4 , Figure 5 It can be obtained that as the upper section limit increases, the lower section limit gradually decreases; as the lower section limit increases, the upper section limit first increases and then decreases.

[0111] In some other embodiments, in order to verify the accuracy of the conclusions analyzed in this application, a simulation model of a new energy transmission system in a certain province is built in the PSASP simulation platform. Figure 6 As shown in the figure, each level of cross section is set according to the actual restricted position. Figure 6 The topology is simplified to Figure 2 The topological structure can be obtained, and the parameters of each reactance are shown in Table 1.

[0112] Table 1 Simplified topology reactance parameters

[0113] parameter Parameter Value parameter Parameter Value <![CDATA[X A ]]> 0.3892(pu) <![CDATA[X AB ]]> 0.931(pu) <![CDATA[X B ]]> 0.23(pu) <![CDATA[X BC ]]> 0.0599(pu) <![CDATA[X C ]]> 0.149(pu) <![CDATA[X CD ]]> 0.1225(pu)

[0114] Set the growth mode to uniform growth, gradually increase the initial output of the new energy station area A, and the cross-section limits of each level are as follows Figure 7 As shown. Figure 7 It can be seen that as the initial output of the new energy station A increases, the limit of the third-level section gradually increases, and the limits of the first and second-level sections first increase and then decrease. Gradually increase the initial output of the new energy station B area, the limits of each level of section are as follows Figure 8 As shown in the figure, as the initial output of the new energy station B increases, the first-level section limit increases first and then decreases, the second-level section limit gradually increases, and the third-level section limit gradually decreases, which is consistent with the theoretical analysis results.

[0115] Combination Figure 7 , Figure 8 It can be seen that in order to improve the overall transmission capacity of the system, that is, to increase the primary section limit, it is necessary to increase the initial output of renewable energy stations A and B within a certain range. The increase in the initial output of the renewable energy stations cannot exceed the initial output of each renewable energy station when the output is evenly distributed.

[0116] In MATLAB / Simulink Figure 7 By fitting the data with formulas, we can obtain the formulas for the influence of the third-level section on the limits of the first- and second-level sections, as shown in formulas (11) and (12):

[0117]

[0118] right Figure 8 By fitting the data, we can get the formula for the influence of the secondary section on the limits of the primary and tertiary sections, as shown in equations (13) and (14). After getting the fitting formula, if the limit of any of the secondary and tertiary sections is known, the limits of the other sections can be calculated.

[0119]

[0120] P3=-2.323×10 -12 P2 5 +4.006×10 -9 P2 4 -2.399×10 -6 P2 3 +0.0004667P2 2 -0.1187P2+225.2

[0121] (14).

[0122] Embodiment 2

[0123] like Fig. 9 As shown, this embodiment provides a system for analyzing the coupling law of multi-stage sections under static voltage stability, including:

[0124] The information acquisition module 901 is used to obtain the topological structure of the new energy transmission system and the output of each new energy station in the new energy transmission system; the topological structure is a multi-stage series section topological structure.

[0125] The decoupling module 902 is used to decouple the topological structure of the new energy transmission system by using the reactance splitting method to obtain a plurality of independent branches; the independent branches include the new energy station, the split reactance and the grid access point.

[0126] The static voltage stability limit calculation module 903 is used to calculate the static voltage stability limit of each independent branch according to the output of the new energy station in each independent branch, the size of the split reactance and the voltage of the grid access point.

[0127] The cross-sectional power expression calculation module 904 is used to determine the cross-sectional power expressions of the new energy transmission system according to the output of each new energy station.

[0128] The output regulation module 905 is used to regulate the output of the renewable energy transmission system until any renewable energy station reaches the static voltage stability limit.

[0129] The formula calculation module 906 is used to determine the limit formulas of each level of sections according to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expressions of each section, and the output of each new energy station at this moment.

[0130] The multi-level section coupling law variation curve construction module 907 is used to determine the multi-level section coupling law variation curve of the section limit according to the section limit formulas of each level.

[0131] Embodiment 3

[0132] This embodiment provides a computer device, which may be a server or a terminal. Its internal structure diagram may be as follows: Fig.10 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used for the multi-level section coupling law change curve data of the section limit. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for analyzing the multi-level section coupling law under static voltage stability is implemented.

[0133] Those skilled in the art will understand that Fig.10 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0134] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0135] Embodiment 4

[0136] This embodiment provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0137] In summary, this application has the following technical effects:

[0138] Current technology has not fully analyzed the coupling laws between multi-level sections under static voltage stability conditions, and the main focus is on transient stability and static power angle stability. This application is committed to filling this gap. Through the method proposed in this application, the topological structure of the renewable energy transmission system is decoupled, and the power-coupled lines are split into independent transmission lines. Subsequently, this application conducted a limit analysis on each renewable energy station, explored the impact of the initial output of the renewable energy station on the section limit, and further analyzed the renewable energy station that first reached the limit as the initial output of the renewable energy station increased, thereby revealing the changing trend of the section limit.

[0139] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0140] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for analyzing the coupling law of multi-stage sections under static voltage stability, characterized in that: include: Obtain the topological structure of the renewable energy transmission system and the output of each renewable energy station in the renewable energy transmission system; The topological structure is a multi-stage series cross-section topological structure; By using the reactance splitting method, the topological structure of the new energy transmission system is decoupled to obtain a plurality of independent branches; the independent branches include the new energy station, the split reactance and the grid access point; According to the output of the new energy station in each independent branch, the size of the split reactance and the voltage at the grid access point, the static voltage stability limit of each independent branch is calculated respectively; According to the output of each new energy station, determine the power expression of each section of the new energy transmission system; Adjusting the output of the renewable energy transmission system until any renewable energy station reaches a static voltage stability limit; According to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expression of each section and the output of each new energy station at this moment, the limit formula of each section is determined; According to the limit formulas of each level of sections, the multi-level section coupling law change curve of section limit is determined.

2. The method for analyzing the coupling law of multi-stage sections under static voltage stability according to claim 1 is characterized in that: According to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expression of each section and the output of each new energy station at this moment, the limit formulas of each level of sections are determined, including: When the renewable energy station farthest from the grid access point in the renewable energy transmission system reaches the static voltage stability limit first, the first formula for the limit of each section is determined based on the power expression of each section and the output of each renewable energy station at this moment; When the new energy station closest to the grid access point in the new energy transmission system reaches the static voltage stability limit first, the second formula for the limit of each section is determined based on the power expression of each section and the output of each new energy station at this moment; When the non-farthest and non-closest renewable energy stations in the renewable energy transmission system reach the static voltage stability limit first, the third formula for the limits of each level of sections is determined based on the power expression of each section and the output of each renewable energy station at this moment.

3. The method for analyzing the coupling law of multi-stage sections under static voltage stability according to claim 2 is characterized in that: The multi-stage series section topology structure includes the output of several new energy stations, the voltage of the grid access point, the access reactance of each new energy station, the transmission reactance collected by different new energy stations, and the section distribution.

4. The method for analyzing the coupling law of multi-stage sections under static voltage stability according to claim 3 is characterized in that: In the new energy transmission system, when there are three new energy stations, and the distances between the new energy stations A, B, and C and the grid access point decrease in sequence, the power expression of each section of the new energy delivery system is specifically: in, P A , P B , P C For the output of new energy stations A, B, and C, P1, P 2. P 3 is the power of the first, second and third level sections.

5. The method for analyzing the coupling law of multi-stage sections under static voltage stability according to claim 4 is characterized in that: The expression of the split reactance in the independent branch is specifically: Among them, X CD1 , X 11 , X 12 They are respectively new energy station C, new energy station B and new energy station A, which are the reactances after splitting, and X BC The output reactance of the new energy station B and the new energy station C, X CD It is the sending reactance collected by the new energy station C.

6. The method for analyzing the coupling law of multi-stage sections under static voltage stability according to claim 5 is characterized in that: According to the output of the new energy station in each independent branch, the size of the split reactance and the voltage at the grid access point, the static voltage stability limit of each independent branch is calculated respectively, specifically: According to the formula Calculate the static voltage stability limits of the independent branches of the new energy station A, the new energy station B and the new energy station C; Where U is the voltage at the grid access point, X A , X B , X C They are the access reactances of new energy stations A, B, and C respectively. XAB It is the output reactance collected by new energy station A and new energy station B.

7. The method for analyzing the coupling law of multi-stage sections under static voltage stability according to claim 6 is characterized in that: The first formula of the section limit at each level is specifically: The second formula of the section limit at each level is specifically: The third formula of the section limit at each level is specifically: Where k1=k+1, k is the step length; P A0 , P B0 , P C0 It is the initial output of new energy stations A, B, and C.

8. An analysis system for multi-stage cross-section coupling law under static voltage stability, characterized in that: include: An information acquisition module is used to obtain the topological structure of the new energy transmission system and the output of each new energy station in the new energy transmission system; The topological structure is a multi-stage series cross-section topological structure; A decoupling module is used to decouple the topological structure of the new energy transmission system by using a reactance splitting method to obtain a plurality of independent branches; the independent branches include a new energy station, the split reactance and a grid access point; The static stability limit calculation module is used to calculate the static voltage stability limit of each independent branch according to the output of the new energy station in each independent branch, the size of the split reactance, and the voltage of the grid access point; A cross-sectional power expression calculation module is used to determine the cross-sectional power expressions of the new energy transmission system according to the output of each new energy station; An output regulation module, used to regulate the output of the renewable energy transmission system until any renewable energy station reaches a static voltage stability limit; The formula calculation module is used to determine the limit formulas of each section according to the order in which the new energy stations in the new energy transmission system reach the static voltage stability limit, the power expression of each section and the output of each new energy station at this moment; The multi-stage section coupling law variation curve construction module is used to determine the multi-stage section coupling law variation curve of the section limit according to the section limit formulas of each level.

9. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method for analyzing the coupling law of multi-level sections under static voltage stability as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a method for analyzing the coupling law of multiple sections under static voltage stability according to any one of claims 1 to 7 is implemented.

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