Power system node voltage-active power sensitivity calculation method and system

Abstract

The present invention provides a method and system for calculating the voltage-active sensitivity of power system nodes, which belongs to the technical field of power system operation control, wherein the method includes constructing an admittance matrix of nonlinear nodes in the power system; inverting the admittance matrix of the nonlinear nodes to obtain an impedance matrix of the nonlinear nodes in the power system; determining the reactance matrix of the nonlinear nodes in the power system according to the impedance matrix of the nonlinear nodes as a first reactance matrix; constructing a reactance matrix of approximate nonlinear nodes in the power system as a second reactance matrix; determining the relationship between the active power injected into each nonlinear node in the power system and the voltage change of any nonlinear node according to the first reactance matrix and the second reactance matrix to determine the voltage sensitivity of each nonlinear node. The method of the present invention can be used for transient voltage stability analysis, is not limited to traditional power grids, and can also be used for power grids containing a high proportion of renewable energy, and has good adaptability and robustness.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system operation control, and in particular relates to a method and system for calculating node voltage-active power sensitivity of a power system. Background Art

[0002] Voltage-active power sensitivity refers to the degree of change in voltage at a node or other nodes in a power system when the active power injected into the node changes. It quantitatively describes the sensitivity of voltage to a certain active power change. Voltage-active power sensitivity plays an important role in the planning, operation and control of power systems. It can help analyze the voltage stability of power systems, determine the installation location and capacity of reactive power compensation equipment, evaluate the impact of different operating parameter changes on voltage, etc., so as to achieve optimized operation of power systems and effective control of voltage.

[0003] Compared with traditional power systems dominated by synchronous generators, the dynamic characteristics of high-penetration renewable energy power systems have more complex dynamic characteristics, especially in terms of primary energy characteristics, component quantity type and time scale. In the transition stage from traditional power systems to modern power systems with high penetration of renewable energy, various dynamic characteristics influence each other, and the dynamic process is particularly complex. One of the main reasons why the grid connection of renewable energy generation has a huge impact on the short-term voltage stability of the power grid is that as an active power injection source, it usually does not provide voltage support. Therefore, it is of great significance to explore the impact of changes in active power injection at nodes of renewable energy on voltage amplitude and short-term voltage stability.

[0004] However, there are few studies on how to calculate the voltage-active power sensitivity in power systems, and the impact of active power injection changes on voltage amplitude and short-term voltage stability is unclear. Therefore, there is an urgent need for an analyzable method for calculating the voltage-active power sensitivity of power system nodes that is suitable for voltage stability analysis. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method and system for calculating node voltage-active power sensitivity of a power system.

[0006] In a first aspect, the present invention provides a method for calculating node voltage-active power sensitivity of a power system, comprising:

[0007] Construct the admittance matrix of nonlinear nodes in the power system;

[0008] The admittance matrix of the nonlinear node is inverted to obtain the impedance matrix of the nonlinear node in the power system;

[0009] Determining a reactance matrix of a nonlinear node in the power system according to an impedance matrix of the nonlinear node as a first reactance matrix;

[0010] constructing a reactance matrix of an approximate nonlinear node in the power system as a second reactance matrix;

[0011] The relationship between the active power injected into each nonlinear node in the power system and the voltage change of any nonlinear node is determined according to the first reactance matrix and the second reactance matrix to determine the voltage sensitivity of each nonlinear node.

[0012] Optionally, constructing the admittance matrix of the nonlinear node in the power system includes:

[0013] Construct the admittance matrix Y of the nonlinear node CC The expression is:

[0014] ;

[0015] in, is the initial admittance matrix of the nonlinear node; is the initial mutual admittance matrix between nonlinear nodes and passive nodes; is the initial admittance matrix of the passive node; is the initial mutual admittance matrix between the passive nodes and the nonlinear nodes.

[0016] Optionally, determining a reactance matrix of a nonlinear node in the power system according to an impedance matrix of the nonlinear node as a first reactance matrix includes:

[0017] Construct the first reactance matrix X CC The expression is:

[0018] X CC =Im(Z CC );

[0019] Among them, Im(·) represents the operation of taking the imaginary part of a complex number; Z CC is the impedance matrix of the nonlinear node; , Y CC is the admittance matrix of the nonlinear node.

[0020] Optionally, constructing a reactance matrix of an approximate nonlinear node in the power system as a second reactance matrix includes:

[0021] Constructing the second reactance matrix The expression is:

[0022] ;

[0023] Among them, Im(·) represents the operation of taking the imaginary part of a complex number; diag -1 (·) means converting the vector into a diagonal matrix and then taking the inverse; is the voltage vector V of the nonlinear node C conjugation of; The impedance matrix Z of the nonlinear node CC The conjugation of.

[0024] Optionally, determining the relationship between the active power injected into each nonlinear node in the power system and the voltage of any nonlinear node according to the first reactance matrix and the second reactance matrix to determine the voltage sensitivity of each nonlinear node includes:

[0025] Get the voltage V of the tth nonlinear node in the power system Ct and the injected active power P Ct ;

[0026] Get the voltage V of the pth nonlinear node in the power system Cp ;

[0027] Construct the expression of the relationship between the active power injected into each nonlinear node and the voltage change of any nonlinear node:

[0028] ;

[0029] in, represents the relationship between the active power injected by the pth nonlinear node and the voltage of the qth nonlinear node; n is the total number of nonlinear nodes in the power system; x pt is the mutual reactance between the pth nonlinear node and the tth nonlinear node; is the second reactance matrix The element in the t-th row and q-th column; Re(·) represents the real part operation of a complex number; Im(·) represents the imaginary part operation of a complex number; |·| represents the modulo operation.

[0030] In a second aspect, the present invention provides a power system node voltage-active power sensitivity calculation system, comprising:

[0031] A first building block is used to build an admittance matrix of a nonlinear node in a power system;

[0032] An inversion module is used to invert the admittance matrix of the nonlinear node to obtain the impedance matrix of the nonlinear node in the power system;

[0033] A first determination module, configured to determine a reactance matrix of a nonlinear node in the power system according to an impedance matrix of the nonlinear node, as a first reactance matrix;

[0034] A second construction module is used to construct a reactance matrix of an approximate nonlinear node in the power system as a second reactance matrix;

[0035] The second determination module is used to determine the change relationship between the active power injected into each nonlinear node in the power system and the voltage of any nonlinear node according to the first reactance matrix and the second reactance matrix, so as to determine the voltage sensitivity of each nonlinear node.

[0036] Optionally, the first building block includes:

[0037] The first construction unit is used to construct the admittance matrix Y of the nonlinear node CC The expression is:

[0038] ;

[0039] in, is the initial admittance matrix of the nonlinear node; is the initial mutual admittance matrix between nonlinear nodes and passive nodes; is the initial admittance matrix of the passive node; is the initial mutual admittance matrix between the passive nodes and the nonlinear nodes.

[0040] Optionally, the first determining module includes:

[0041] The second construction unit is used to construct the first reactance matrix X CC The expression is:

[0042] X CC =Im(Z CC );

[0043] Among them, Im(·) represents the operation of taking the imaginary part of a complex number; Z CC is the impedance matrix of the nonlinear node; , Y CC is the admittance matrix of the nonlinear node.

[0044] Optionally, the second building block includes:

[0045] The third construction unit is used to construct the second reactance matrix The expression is:

[0046] ;

[0047] Among them, Im(·) represents the operation of taking the imaginary part of a complex number; diag -1 (·) means converting the vector into a diagonal matrix and then taking the inverse; is the voltage vector V of the nonlinear node C conjugation of; The impedance matrix Z of the nonlinear node CC The conjugation of.

[0048] Optionally, the second determining module includes:

[0049] The first acquisition unit is used to acquire the voltage V of the tth nonlinear node in the power system Ct and the injected active power P Ct ;

[0050] The second acquisition unit is used to acquire the voltage V of the pth nonlinear node in the power system. Cp ;

[0051] The fourth construction unit is used to construct an expression for the relationship between the active power injected into each nonlinear node and the voltage of any nonlinear node:

[0052] ;

[0053] in, represents the relationship between the active power injected by the pth nonlinear node and the voltage of the qth nonlinear node; n is the total number of nonlinear nodes in the power system; x pt is the mutual reactance between the pth nonlinear node and the tth nonlinear node; is the second reactance matrix The element in the t-th row and q-th column; Re(·) represents the real part operation of a complex number; Im(·) represents the imaginary part operation of a complex number; |·| represents the modulo operation. Beneficial Effects

[0054] The present invention provides a method and system for calculating voltage-active power sensitivity of power system nodes, which focuses on the relationship between active power injection change and voltage and can be used for transient voltage stability analysis. At the same time, the voltage-active power sensitivity calculation method in the present invention is not limited to traditional power grids, but can also be used in power grids with a high proportion of renewable energy, and has good adaptability and robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 A schematic diagram of a flow chart of a method for calculating voltage-active power sensitivity of a power system node provided by an embodiment of the present invention;

[0057] Figure 2 The voltage collapse calculation example of the China Electric Power Research Institute standard calculation example provided by the embodiment of the present invention Heatmap;

[0058] Figure 3The voltage-active power sensitivity heat map of the sending and receiving ends of the IEEE 4-machine 11-node system example provided in the embodiment of the present invention;

[0059] Figure 4 A non-linear power supply voltage-active power sensitivity thermodynamic diagram provided by an embodiment of the present invention;

[0060] Figure 5 A non-linear load voltage-active power sensitivity thermodynamic diagram provided by an embodiment of the present invention;

[0061] Figure 6 A schematic diagram of the structure of a power system node voltage-active power sensitivity calculation system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0063] like Figure 1 As shown, this embodiment provides a method for calculating node voltage-active power sensitivity of a power system, including:

[0064] Step 101: construct an admittance matrix of nonlinear nodes in a power system.

[0065] In this embodiment, the nodes in the power system are divided into passive nodes (no injected current at this type of node), linear nodes (the injected current expression of this type of node will not affect the explicit solution of the original network equation) and nonlinear nodes (the injected current expression of this type of node affects the explicit solution of the network equation).

[0066] The constructed network equation is:

[0067] .

[0068] in, is the initial admittance matrix of the linear node; is the initial mutual admittance matrix between linear nodes and passive nodes; is the initial mutual admittance matrix between linear nodes and nonlinear nodes; is the initial mutual admittance matrix between the passive nodes and the linear nodes; is the initial admittance matrix of the passive node; is the initial mutual admittance matrix between the passive nodes and the nonlinear nodes; is the initial mutual admittance matrix between nonlinear nodes and linear nodes; is the initial mutual admittance matrix between nonlinear nodes and passive nodes; is the initial admittance matrix of the nonlinear node; V S is the voltage vector of the linear node; V N is the voltage vector of the passive node; V C is the voltage vector of the nonlinear node; I S is the injected current vector of the linear node; . / represents element-by-element division; is the voltage vector V at the linear node S conjugation of; is the voltage vector V of the nonlinear node C In this embodiment, represents the conjugate of y.

[0069] by and For example, if The dimension of is n×m, then The dimension is m×n.

[0070] Perform Cronus reduction on the network equation to eliminate passive nodes and obtain the reduced network equation:

[0071] .

[0072] Among them, Y SS for Reduced-order admittance matrix; ; Express The inverse of Y SC for Reduced-order admittance matrix; ; Express Take the inverse; Y CS for Reduced-order admittance matrix; ; Y CC for Reduced-order admittance matrix; .

[0073] Step 102: Invert the admittance matrix of the nonlinear node to obtain the impedance matrix of the nonlinear node in the power system.

[0074] In this embodiment, the impedance matrix of the nonlinear node in the power system is .

[0075] Step 103: Determine a reactance matrix of the nonlinear nodes in the power system according to the impedance matrix of the nonlinear nodes to serve as a first reactance matrix.

[0076] In this embodiment, the first reactance matrix X constructed CC The expression is:

[0077] X CC =Im(Z CC ).

[0078] Here, Im(·) represents the operation of taking the imaginary part of a complex number.

[0079] Step 104: construct a reactance matrix of an approximate nonlinear node in the power system as a second reactance matrix.

[0080] Exemplarily, the second reactance matrix constructed is The expression is:

[0081] .

[0082] Among them, Im(·) represents the operation of taking the imaginary part of a complex number; diag -1 (·) means converting the vector into a diagonal matrix and then taking the inverse; is the voltage vector V of the nonlinear node C conjugation of; The impedance matrix Z of the nonlinear node CC The conjugation of.

[0083] Step 105: Determine the relationship between the active power injected into each nonlinear node in the power system and the voltage of any nonlinear node according to the first reactance matrix and the second reactance matrix to determine the voltage sensitivity of each nonlinear node.

[0084] From the reduced network equation we can get:

[0085] ;

[0086] .

[0087] Linearize the above equation in this step:

[0088] Assume that the node power is S C Change to S C +ΔS C , then the voltage will be V C Change to V C +ΔV C ,get:

[0089] .

[0090] Further neglecting the quadratic term, we get:

[0091] .

[0092] In this embodiment, M is replaced , use I C Replace Y CC V C +Y CS V S We can get:

[0093] .

[0094] For any two complex numbers z and w, the following holds:

[0095] .

[0096] Therefore, we can get:

[0097] .

[0098] Further we can get:

[0099] .

[0100] Let ΔS C =ΔP C ,So:

[0101] .

[0102] Generally due to Y CC The order of magnitude is usually 10 2 , we get:

[0103] ;

[0104] .

[0105] Where I is the identity matrix.

[0106] Further neglecting the resistance, we get:

[0107] .

[0108] Also because , Indicates that it is much greater than, and we get:

[0109] .

[0110] Here, j represents an imaginary unit.

[0111] It is known that for any two complex numbers z and w, the following holds:

[0112] .

[0113] get:

[0114] .

[0115] Here, Re(·) represents the real part operation of a complex number; .* represents element-by-element multiplication, following the rules of MATLAB.

[0116] Therefore, the expression Substitution You can get:

[0117] .

[0118] Exemplarily, this step includes:

[0119] Get the voltage V of the tth nonlinear node in the power system Ct and the injected active power P Ct .

[0120] Get the voltage V of the pth nonlinear node in the power system Cp .

[0121] Construct the expression of the relationship between the active power injected into each nonlinear node and the voltage change of any nonlinear node:

[0122] .

[0123] in, represents the relationship between the active power injected by the pth nonlinear node and the voltage of the qth nonlinear node, that is, the sensitivity of the qth nonlinear node voltage to the active power injected by the pth nonlinear node; n is the total number of nonlinear nodes in the power system; x pt is the mutual reactance between the pth nonlinear node and the tth nonlinear node, that is, the first reactance matrix X CC The element at row p and column t in ; is the second reactance matrix The element in the t-th row and q-th column; Re(·) represents the real part operation of a complex number; Im(·) represents the imaginary part operation of a complex number; |·| represents the modulo operation.

[0124] In verification When calculating the characteristics, the voltage collapse calculation example of the standard calculation example of China Electric Power Research Institute is used, the transient potential constant model is used for the synchronous machine, the transient reactance is 0.1, and the load is of constant power type. The expression pair Calculate and draw a heat map, such as Figure 2 shown. Figure 2 Shown The property of is that it is a block diagonally dominant square matrix.

[0125] In such Figure 3 When verifying this embodiment in the IEEE 4-machine 11-node system example sending and receiving end system shown in the figure, the synchronous machine adopts a transient potential constant model, the transient reactance is 0.3, the load is a constant power type, the photovoltaic outer ring adopts fixed active power and fixed reactive power control, and the line resistance is ignored. On the basis of the original example, the synchronous generator at node 1 is replaced with a 300MW photovoltaic power station; a 100MW photovoltaic power station is added at node 5; the load at node 7 is removed; and the output of the synchronous generator at node 2 is changed to 300MW. The sending and receiving end system is calculated according to the calculation method provided in this embodiment, and the results are as follows Figure 3 As shown, the voltage-active power sensitivity matrix of the sending-end and receiving-end systems is a block diagonal dominant matrix, and the voltage-active power sensitivity of the corresponding nodes of the sending-end system is negative, and the voltage-active power sensitivity of the corresponding nodes of the receiving-end system is positive.

[0126] In such Figure 4 When verifying this embodiment using the voltage collapse example of the standard example of the China Electric Power Research Institute shown in the figure, the synchronous machine adopts a transient potential constant model, the transient reactance is 0.1, the load is a constant power and constant impedance type, the photovoltaic outer ring adopts fixed active power and fixed reactive power control, and the line resistance is ignored.

[0127] Figure 4 This is the non-linear power supply voltage-active power sensitivity thermodynamic diagram of the voltage collapse calculation example of the China Electric Power Research Institute standard calculation example. At this time, all 13 generators are set as synchronous generators, the constant power load penetration rate is 40%, and the constant impedance penetration rate is 60%. The calculation method provided in this embodiment is used to calculate the voltage collapse calculation example of the China Electric Power Research Institute standard calculation example, and the results are as follows: Figure 4 As shown, the voltage-active power sensitivity matrix of this China Electric Power Research Institute standard example voltage collapse example is a block diagonal dominant matrix, and the voltage-active power sensitivity is all positive.

[0128] like Figure 5 As shown in the figure, the voltage collapse calculation example of the China Electric Power Research Institute standard calculation example is a non-linear power supply voltage-active power sensitivity thermodynamic diagram. At this time, 9 units are set as synchronous generators, 4 units are set as photovoltaics, and the load type is full constant impedance. According to the calculation method provided in this implementation, the voltage collapse calculation example of the China Electric Power Research Institute standard calculation example is calculated, and the results are as follows Figure 5 As shown in FIG. 1 , the voltage-active power sensitivity matrix of the voltage collapse calculation example of the China Electric Power Research Institute standard calculation example is a block diagonal dominant matrix, and the voltage-active power sensitivity is all negative.

[0129] In summary, the power system node voltage-active power sensitivity calculation method provided in this embodiment focuses on the relationship between the active power injection change and the voltage. It can be used for transient voltage stability analysis based on the network equation. At the same time, the voltage-active power sensitivity calculation method in this embodiment is not limited to traditional power grids, but can also be used for power grids with a high proportion of new energy. It has good adaptability and robustness. Finally, its effectiveness is verified through MATLAB simulation. Example 2

[0130] Based on the same inventive concept as Example 1, this embodiment provides a power system node voltage-active power sensitivity calculation system. Since the principle of solving the problem by this system is similar to the power system node voltage-active power sensitivity calculation method provided in the aforementioned Example 1, the implementation of this system can refer to the implementation of the power system node voltage-active power sensitivity calculation method provided in Example 1.

[0131] like Figure 6 As shown, the power system node voltage-active power sensitivity calculation system includes:

[0132] The first building module is used to build the admittance matrix of the nonlinear nodes in the power system.

[0133] The inversion module is used to invert the admittance matrix of the nonlinear node to obtain the impedance matrix of the nonlinear node in the power system.

[0134] The first determination module is used to determine the reactance matrix of the nonlinear nodes in the power system according to the impedance matrix of the nonlinear nodes to serve as the first reactance matrix.

[0135] The second construction module is used to construct a reactance matrix of an approximate nonlinear node in the power system as a second reactance matrix.

[0136] The second determination module is used to determine the change relationship between the active power injected into each nonlinear node in the power system and the voltage of any nonlinear node according to the first reactance matrix and the second reactance matrix, so as to determine the voltage sensitivity of each nonlinear node.

[0137] Exemplarily, the first building block includes:

[0138] The first construction unit is used to construct the admittance matrix Y of the nonlinear node CC The expression is:

[0139] .

[0140] in, is the initial admittance matrix of the nonlinear node; is the initial mutual admittance matrix between nonlinear nodes and passive nodes; is the initial admittance matrix of the passive node; is the initial mutual admittance matrix between the passive nodes and the nonlinear nodes.

[0141] Exemplarily, the first determining module includes:

[0142] The second construction unit is used to construct the first reactance matrix X CC The expression is:

[0143] X CC =Im(Z CC ).

[0144] Among them, Im(·) represents the operation of taking the imaginary part of a complex number; Z CC is the impedance matrix of the nonlinear node; , Y CC is the admittance matrix of the nonlinear node.

[0145] Exemplarily, the second building block includes:

[0146] The third construction unit is used to construct the second reactance matrix The expression is:

[0147] .

[0148] Among them, Im(·) represents the operation of taking the imaginary part of a complex number; diag -1 (·) means converting the vector into a diagonal matrix and then taking the inverse; is the voltage vector V of the nonlinear node C conjugation of; The impedance matrix Z of the nonlinear node CC The conjugation of.

[0149] Exemplarily, the second determining module includes:

[0150] The first acquisition unit is used to acquire the voltage V of the tth nonlinear node in the power system Ct and the injected active power P Ct .

[0151] The second acquisition unit is used to acquire the voltage V of the pth nonlinear node in the power system. Cp .

[0152] The fourth construction unit is used to construct an expression for the relationship between the active power injected into each nonlinear node and the voltage of any nonlinear node:

[0153] .

[0154] in, represents the relationship between the active power injected by the pth nonlinear node and the voltage of the qth nonlinear node; n is the total number of nonlinear nodes in the power system; x pt is the mutual reactance between the pth nonlinear node and the tth nonlinear node; is the second reactance matrix The element in the t-th row and q-th column; Re(·) represents the real part operation of a complex number; Im(·) represents the imaginary part operation of a complex number; |·| represents the modulo operation.

[0155] For more specific working processes of the above modules, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here. Example 3

[0156] This embodiment provides a computer device, including a processor and a memory; wherein the processor implements the steps of the power system node voltage-active power sensitivity calculation method described in Embodiment 1 when executing a computer program stored in the memory.

[0157] For more specific details of the above method, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here. Example 4

[0158] This embodiment provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the method for calculating the node voltage-active power sensitivity of the power system described in Embodiment 1 are implemented.

[0159] For more specific details of the above method, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here. Example 5

[0160] This embodiment provides a computer program product, including computer executable instructions or a computer program. When the computer executable instructions or the computer program are executed by a processor, the steps of the power system node voltage-active power sensitivity calculation method described in Embodiment 1 are implemented.

[0161] For more specific details of the above method, please refer to the corresponding contents disclosed in Example 1, which will not be repeated here.

[0162] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the systems, devices, storage media, and computer program products disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0163] Those skilled in the art can clearly understand that the technology in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution in the embodiments of the present invention can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention or certain parts of the embodiments.

[0164] In some embodiments, computer executable instructions may be in the form of a program, software, software module, script or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment.

[0165] As an example, computer-executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file storing other programs or data, such as in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or code portions).

[0166] As an example, computer executable instructions may be deployed to be executed on one electronic device, or on multiple electronic devices located at one site, or on multiple electronic devices distributed at multiple sites and interconnected by a communication network.

[0167] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for calculating node voltage-active power sensitivity of a power system, characterized in that: include: Construct the admittance matrix of nonlinear nodes in the power system; The admittance matrix of the nonlinear node is inverted to obtain the impedance matrix of the nonlinear node in the power system; Determining a reactance matrix of a nonlinear node in the power system according to an impedance matrix of the nonlinear node as a first reactance matrix; The reactance matrix of the approximate nonlinear node in the power system is constructed as the second reactance matrix, which includes: Construct the second reactance matrix The expression is: ； Among them, Im(·) represents the operation of taking the imaginary part of a complex number; It means converting the vector into a diagonal matrix and then taking the inverse; is the voltage vector V of the nonlinear node C conjugation of; The impedance matrix Z of the nonlinear node CC conjugation of; The relationship between the active power injected into each nonlinear node in the power system and the voltage change of any nonlinear node is determined according to the first reactance matrix and the second reactance matrix to determine the voltage sensitivity of each nonlinear node, including: Get the voltage V of the tth nonlinear node in the power system Ct and the injected active power P Ct ; Get the voltage V of the pth nonlinear node in the power system Cp ; Construct the expression of the relationship between the active power injected into each nonlinear node and the voltage change of any nonlinear node: ； in, represents the relationship between the active power injected by the pth nonlinear node and the voltage of the qth nonlinear node; n is the total number of nonlinear nodes in the power system; x pt is the mutual reactance between the pth nonlinear node and the tth nonlinear node; is the second reactance matrix The element in the t-th row and q-th column; Re(·) represents the real part operation of the complex number; |·| represents the modulo operation.

2. The method for calculating the node voltage-active power sensitivity of a power system according to claim 1, characterized in that: The method of constructing an admittance matrix of a nonlinear node in a power system includes: Construct the admittance matrix Y of the nonlinear node CC The expression is: ； in, is the initial admittance matrix of the nonlinear node; is the initial mutual admittance matrix between nonlinear nodes and passive nodes; is the initial admittance matrix of the passive node; is the initial mutual admittance matrix between the passive nodes and the nonlinear nodes.

3. The method for calculating the node voltage-active power sensitivity of a power system according to claim 1, characterized in that: The step of determining the reactance matrix of the nonlinear node in the power system according to the impedance matrix of the nonlinear node as a first reactance matrix includes: Construct the first reactance matrix X CC The expression is: X CC =Im(Z CC ); Among them, Im(·) represents the operation of taking the imaginary part of a complex number; Z CC is the impedance matrix of the nonlinear node; , Y CC is the admittance matrix of the nonlinear node.

4. A power system node voltage-active power sensitivity calculation system, characterized in that: include: A first building block is used to build an admittance matrix of a nonlinear node in a power system; An inversion module is used to invert the admittance matrix of the nonlinear node to obtain the impedance matrix of the nonlinear node in the power system; A first determination module, configured to determine a reactance matrix of a nonlinear node in the power system according to an impedance matrix of the nonlinear node, as a first reactance matrix; A second construction module is used to construct a reactance matrix of an approximate nonlinear node in the power system as a second reactance matrix; The second building block comprises: The third construction unit is used to construct the second reactance matrix The expression is: ； Among them, Im(·) represents the operation of taking the imaginary part of a complex number; It means converting the vector into a diagonal matrix and then taking the inverse; is the voltage vector V of the nonlinear node C conjugation of; The impedance matrix Z of the nonlinear node CC conjugation of; The second determination module is used to determine the change relationship between the active power injected into each nonlinear node in the power system and the voltage of any nonlinear node according to the first reactance matrix and the second reactance matrix to determine the voltage sensitivity of each nonlinear node, and the second determination module includes: The first acquisition unit is used to acquire the voltage V of the tth nonlinear node in the power system Ct and the injected active power P Ct ; The second acquisition unit is used to acquire the voltage V of the pth nonlinear node in the power system. Cp ; The fourth construction unit is used to construct an expression for the relationship between the active power injected into each nonlinear node and the voltage of any nonlinear node: ； in, represents the relationship between the active power injected by the pth nonlinear node and the voltage of the qth nonlinear node; n is the total number of nonlinear nodes in the power system; x pt is the mutual reactance between the pth nonlinear node and the tth nonlinear node; is the second reactance matrix The element in the t-th row and q-th column; Re(·) represents the real part operation of the complex number; |·| represents the modulo operation.

5. The power system node voltage-active power sensitivity calculation system according to claim 4, characterized in that: The first building block comprises: The first construction unit is used to construct the admittance matrix Y of the nonlinear node CC The expression is: ； in, is the initial admittance matrix of the nonlinear node; is the initial mutual admittance matrix between nonlinear nodes and passive nodes; is the initial admittance matrix of the passive node; is the initial mutual admittance matrix between the passive nodes and the nonlinear nodes.

6. The power system node voltage-active power sensitivity calculation system according to claim 4, characterized in that: The first determining module comprises: The second construction unit is used to construct the first reactance matrix X CC The expression is: X CC =Im(Z CC ); Among them, Im(·) represents the operation of taking the imaginary part of a complex number; Z CC is the impedance matrix of the nonlinear node; , Y CC is the admittance matrix of the nonlinear node.

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