Static voltage stability evaluation method and apparatus, terminal device, and storage medium

Abstract

Disclosed in the present invention are a static voltage stability evaluation method and apparatus, a terminal device, and a storage medium. The method comprises: acquiring operation data of nodes in an active power distribution network and connection relationships between all the nodes; constructing a full Jacobian matrix of the active power distribution network and inverter droop control model equations; further constructing an extended Jacobian matrix; then acquiring the operation data of the nodes, and calculating the minimum eigenvalue of the extended Jacobian matrix on the basis of the operation data; and performing static voltage stability evaluation on the basis of the minimum eigenvalue. The present invention fully takes into account the dynamic characteristics of an inverter control mode under renewable energy grid connection during static voltage stability evaluation, thereby improving the accuracy of static stability evaluation of the active power distribution network under the renewable energy grid connection, and providing a guarantee for the static stable operation of the active power distribution network.

Description

A static voltage stability evaluation method and device, a terminal device and a storage medium TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, and in particular to a static voltage stability evaluation method, device, terminal device and storage medium. BACKGROUND

[0002] Developing high-proportion new energy power systems is the general trend of future power systems, but the high-proportion new energy access will bring many problems and challenges to the power grid, among which the problems caused by new energy to the static stability operation of the power grid are particularly prominent. First, high-proportion new energy will introduce high-proportion power electronic devices, and the "double high" characteristics of the power system will change and further complicate the static voltage stability mechanism, which may lead to the failure of traditional stability analysis. Secondly, due to the fluctuation and randomness of new energy output, as well as the volatility of load, the high-proportion new energy power system is prone to source-load imbalance, affecting the static stability operation of the power grid. In addition, the active regulation of new energy is limited and does not have dynamic reactive power support capability, resulting in a decrease in voltage stability, and even causing large-scale new energy collective off-grid accidents. Therefore, it is extremely important to realize reliable and efficient active distribution network static voltage stability evaluation to ensure the static stability operation of the power grid.

[0003] The traditional static voltage stability evaluation method is quite mature, and the current static voltage stability evaluation method after new energy grid connection is derived by modifying the traditional method according to the output characteristics and dynamics of new energy. However, in fact, the control mode of the grid-connected inverter has a significant impact on the system voltage stability margin, but the existing distribution network static voltage stability evaluation method does not fully consider the dynamic characteristics of the control mode of the grid-connected inverter, so it is necessary to study the static voltage evaluation problem under the control mode of the inverter to better realize the static voltage stability control of the distribution network under the grid connection of new energy. SUMMARY

[0004] The present application provides a static voltage stability evaluation method, device, terminal device and storage medium to solve the technical problem that the prior art cannot accurately evaluate the static voltage stability of the active distribution network under the grid connection of new energy.

[0005] To solve the above technical problems, the present application provides a static voltage stability evaluation method, comprising:

[0006] Obtaining the operation data of each node in the active distribution network and the connection relationship between all nodes; wherein the operation data includes voltage amplitude and phase angle;

[0007] For each node in the active distribution network, according to the connection relationship, the active power equation and the reactive power equation of the node are constructed;

[0008] constructing a full Jacobian matrix of the active power distribution network according to active power equations and reactive power equations of all nodes in the active power distribution network;

[0009] constructing an inverter droop control mode equation of each node in the active power distribution network;

[0010] constructing an extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equation of all nodes in the active power distribution network;

[0011] substituting operation data of each node in the active power distribution network into the extended Jacobian matrix, and calculating a minimum eigenvalue of the extended Jacobian matrix;

[0012] judging whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue.

[0013] As a preferred solution, the constructing the active power equation and the reactive power equation of the node according to the connection relationship comprises:

[0014] determining a plurality of adjacent nodes of the node according to the connection relationship;

[0015] constructing the active power equation and the reactive power equation of the node according to the node and all the adjacent nodes;

[0016] wherein, the expression of the active power equation is:

[0017] the expression of the reactive power equation is:

[0018] wherein, ΔP i represents a change amount of the injected active power of the node i; represents the power injected active power of the node i; represents the load active power of the node i; ΔQ i represents a change amount of the injected reactive power of the node i; represents the power injected reactive power of the node i; represents the load reactive power of the node i; U i represents the voltage amplitude of the node i; U j represents the voltage amplitude of the node j; j∈i represents the node j connected with the node i; θ ij represents the phase angle between the node i and the node j; G ij is the real part of the admittance between the node i and the node j; B ij is the imaginary part of the admittance between the node i and the node j.

[0019] As a preferred solution, the expression of the full Jacobian matrix is:

[0020] where the expression of the diagonal elements of the full Jacobian matrix is:

[0021] The expression of the off-diagonal elements of the full Jacobian matrix is:

[0022] where J f represents the full Jacobian matrix; n is the number of PV nodes in the active distribution network; r is the number of PQ nodes in the active distribution network; H f , N f , M f and L f represent block matrices; G ii is the real part of the self-admittance of node i; B ii is the imaginary part of the self-admittance of node i.

[0023] As a preferred solution, the construction of the inverter droop control mode equation of the node comprises:

[0024] constructing an inverter droop control mode equation of the node considering droop control and inverse droop control;

[0025] where the expression of the inverter droop control mode equation is:

[0026] The expression of the |V|-P droop control dynamic characteristic is:

[0027] The expression of the |V|-Q droop control dynamic characteristic is:

[0028] where, is the positive droop active coefficient of the generator on node i; is the positive droop reactive coefficient of the generator on node i; is the reference voltage amplitude of node i; is the reference active power of the generator on node i when the voltage amplitude is the reference voltage amplitude; is the reference reactive power of the generator on node i when the voltage amplitude is the reference voltage amplitude; is the minimum active power of the generator on node i; is the maximum active power of the generator on node i; is the minimum reactive power of the generator on node i; is the maximum reactive power of the generator on node i.

[0029] As a preferred solution, the constructing the extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equations of all nodes in the active power distribution network comprises:

[0030] constructing an initial extended Jacobian matrix according to the full Jacobian matrix and a preset reference node;

[0031] constructing the extended Jacobian matrix according to the initial extended Jacobian matrix and the inverter droop control mode equations of all nodes in the active power distribution network;

[0032] wherein, the expression of the initial extended Jacobian matrix is:

[0033] wherein, J E0 represents the initial extended Jacobian matrix; H E0 , N E0 , M E0 and L E0 represent block matrices, if node k is a reference node, then H E0 is the matrix obtained by deleting the kth row and the kth column of H f ; N E0 is the matrix obtained by deleting the kth row and the kth column of H f ; M E0 is the matrix obtained by deleting the kth row and the kth column of H f ; and L E0 is the matrix obtained by deleting the kth row and the kth column of H f .

[0034] the expression of the extended Jacobian matrix is:

[0035] the expression of the diagonal element of the extended Jacobian matrix is:

[0036] the expression of the non-diagonal element of the extended Jacobian matrix is:

[0037] wherein, J E represents the extended Jacobian matrix; H E , N E , M E and L E represent block matrices.

[0038] As a preferred solution, the judging whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue comprises:

[0039] determining whether the minimum eigenvalue is greater than zero; if yes, determining that the active power distribution network is static voltage stable; otherwise, determining that the active power distribution network is static voltage unstable.

[0040] As a preferred solution, after determining whether the active power distribution network is static voltage stable according to the minimum eigenvalue, the method further comprises:

[0041] Taking the real part of the minimum eigenvalue as a voltage stability margin index, the active power distribution network is regulated.

[0042] On the basis of the above-mentioned embodiments, another embodiment of the present application provides a static voltage stability evaluation device, comprising: a data information acquisition module, a full Jacobian matrix construction module, an inverter droop control mode equation construction module, an extended Jacobian matrix construction module and a static voltage stability evaluation module.

[0043] The data information acquisition module is configured to acquire operation data of each node in the active power distribution network and connection relationships between all nodes; wherein the operation data comprises voltage amplitude and phase angle.

[0044] The full Jacobian matrix construction module is configured to, for each node in the active power distribution network, construct an active power equation and a reactive power equation of the node according to the connection relationships; and construct a full Jacobian matrix of the active power distribution network according to the active power equations and the reactive power equations of all nodes in the active power distribution network.

[0045] The inverter droop control mode equation construction module is configured to, for each node in the active power distribution network, construct an inverter droop control mode equation of the node.

[0046] The extended Jacobian matrix construction module is configured to construct an extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equations of all nodes in the active power distribution network.

[0047] The static voltage stability evaluation module is configured to substitute the operation data of each node in the active power distribution network into the extended Jacobian matrix, and calculate a minimum eigenvalue of the extended Jacobian matrix; and determine whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue.

[0048] On the basis of the above-mentioned embodiments, still another embodiment of the present application provides a terminal device, comprising a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the static voltage stability evaluation method of the above-mentioned embodiments when executing the computer program.

[0049] On the basis of the above-mentioned embodiments, a further embodiment of the application provides a storage medium comprising a stored computer program, wherein the computer program, when executed, controls a device in which the storage medium is located to perform the static voltage stability evaluation method described in the above-mentioned embodiments of the application.

[0050] Compared with the prior art, the embodiments of the application have the following beneficial effects:

[0051] The application obtains the equipment data and connection relationship of the nodes in the active power distribution network, constructs the full Jacobian matrix of the active power distribution network and the inverter droop control mode equation, further constructs the extended Jacobian matrix, then obtains the operation data of the nodes, calculates the minimum eigenvalue of the extended Jacobian matrix according to the operation data, and performs static voltage stability evaluation according to the minimum eigenvalue. BRIEF DESCRIPTION OF DRAWINGS

[0052] Fig. 1 is a flow diagram of a static voltage stability evaluation method according to an embodiment of the application;

[0053] Fig. 2 is a structural diagram of a static voltage stability evaluation device according to another embodiment of the application. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme in the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of the application.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs; the terms used herein are only for the purpose of describing specific embodiments of the application, and are not intended to limit the application; the terms "include" and "have" and any variations thereof in the specification and claims of the application and the above description of drawings are intended to cover non-exclusive inclusion.

[0056] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to those of ordinary skill in the art, embodiments described herein can be combined with other embodiments.

[0057] The technical solutions in the embodiments of the present application will be apparently and completely described in connection with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort fall within the protection scope of the present application.

[0058] Embodiment one

[0059] Please refer to Fig. 1, which is a flowchart of a static voltage stability evaluation method provided by an embodiment of the present application, including:

[0060] S1, obtaining the operation data of each node in the active power distribution network and the connection relationship between all nodes; wherein the operation data includes voltage amplitude and phase angle.

[0061] It should be noted that the evaluation object of the static voltage stability evaluation method provided by the present application is the static voltage of the active power distribution network containing grid-connected inverters.

[0062] In the present embodiment, the voltage amplitude and phase angle of each node in the active power distribution network are obtained by a synchronous phasor measurement device.

[0063] S2, for each node in the active power distribution network, constructing the active power equation and the reactive power equation of the node according to the connection relationship.

[0064] It should be noted that the power flow equation and the power equation of the power system are expressed as follows:

[0065] In the formula, Pi represents the injected complex power of node i, ΔPi represents the change amount of the injected complex power of node i, Pi* represents the given value of the injected complex power of node i, Pi represents the calculated value of the injected complex power of node i.

[0066] In the formula, Pi represents the power injected by the power source of the node, Pi represents the load power of the node.

[0067] wherein, denotes the voltage of the node, denotes the conjugate of the injection current of the node.

[0068] The above formula is a calculation formula of the injection current of the node, wherein, is a node current vector, Y is a system admittance matrix, is a node voltage vector.

[0069] In the following embodiments, according to the connection relationship, a plurality of adjacent nodes of the node are determined, the power flow equation and the power equation of the power system are combined, and the part related to active power and the part related to reactive power are written separately to obtain the active power equation and the reactive power equation of the node.

[0070] In a preferred embodiment, the active power equation and the reactive power equation of the node are constructed according to the connection relationship, comprising:

[0071] According to the connection relationship, a plurality of adjacent nodes of the node are determined;

[0072] According to the device data of the node and all the adjacent nodes, the active power equation and the reactive power equation of the node are constructed;

[0073] wherein, the expression of the active power equation is:

[0074] the expression of the reactive power equation is:

[0075] wherein, ΔP i denotes the change amount of the injection active power of the node i; denotes the injection active power of the power source of the node i; denotes the active power of the load of the node i; ΔQ i denotes the change amount of the injection reactive power of the node i; denotes the injection reactive power of the power source of the node i; denotes the reactive power of the load of the node i; U i denotes the voltage amplitude of the node i; U j denotes the voltage amplitude of the node j; j∈i denotes the node j connected with the node i; θ ij denotes the phase angle between the node i and the node j; G ij is the real part of the admittance between the node i and the node j; B ij is the imaginary part of the admittance between the node i and the node j.

[0076] It should be noted that, Gij and B ij The quantity is known.

[0077] S3. Construct the full Jacobian matrix of the active distribution network based on the active power equations and reactive power equations of all nodes in the active distribution network.

[0078] It should be noted that this method is applicable to power systems containing one balancing node, several PV nodes, and several PQ nodes.

[0079] In a preferred embodiment, the expression for the total Jacobian matrix is:

[0080] The expression for the diagonal elements of the full Jacobian matrix is ​​as follows:

[0081] The expression for the off-diagonal elements of the full Jacobian matrix is:

[0082] In the formula, J f Represents the total Jacobian matrix; n is the number of PV nodes in the active distribution network; r is the number of PQ nodes in the active distribution network; H f N f M f and L f G represents a block matrix; ii B is the real part of the self-admittance of node i; ii Let i be the imaginary part of the self-admittance of node i.

[0083] It should be noted that the full Jacobian matrix in this method is derived from the simplified Jacobian matrix. The derivation process of the full Jacobian matrix is ​​as follows:

[0084] The simplified Jacobian matrix expression for the static equations of a power system is given as:

[0085] In the formula, J represents the full Jacobian matrix; n is the number of PV nodes in the active distribution network; r is the number of PQ nodes in the active distribution network; H is... The block matrix representation; N is The block matrix representation; M is The block matrix representation; L is The block matrix representation.

[0086] For PQ nodes, It is a given constant for PV nodes. If it is a given constant, then Therefore, we have:

[0087] i.e. the injected complex power variation at this time The first-order partial derivative of the voltage amplitude and phase angle with respect to the injected complex power calculation value The expression of the diagonal elements of the simplified Jacobian matrix J is simplified as follows:

[0088] The expression of the non-diagonal elements of the simplified Jacobian matrix J is simplified as follows:

[0089] The full Jacobian matrix is the Jacobian matrix considering the active power equations and the reactive power equations of all nodes. For an m-node system, the full Jacobian matrix is a 2m square matrix. The full Jacobian matrix needs to be modified on the diagonal elements of each block matrix of the simplified Jacobian matrix to obtain the expression of the diagonal elements of the full Jacobian matrix. The calculation method of the non-diagonal elements of each block of the full Jacobian matrix is the same as that of the non-diagonal elements of the simplified Jacobian matrix.

[0090] It should be further noted that the self-admittance of node i is the sum of the admittances of the branches connected to node i, G ii and B ii are known quantities.

[0091] S4, for each node in the active power distribution network, constructing an inverter droop control mode equation of the node.

[0092] In a preferred embodiment, the constructing an inverter droop control mode equation of the node according to the device data comprises:

[0093] constructing an inverter droop control mode equation of the node considering |V|-P droop control and |V|-Q droop control according to the device data;

[0094] wherein the expression of the inverter droop control mode equation is:

[0095] The expression of the |V|-P droop control dynamic characteristic is:

[0096] The expression of the |V|-Q droop control dynamic characteristic is:

[0097] wherein, is the positive droop active coefficient of the generator at node i; is the positive droop reactive coefficient of the generator at node i; is the reference voltage amplitude of node i; is the reference active power of the generator at node i when the voltage amplitude is the reference voltage amplitude; P ref,i is the reference active power of the generator at node i when the voltage amplitude is the reference voltage amplitude; P min,i is the minimum active power of the generator at node i; P max,i is the maximum active power of the generator at node i; Q min,i is the minimum reactive power of the generator at node i; Q max,i is the maximum reactive power of the generator at node i.

[0098] It should be noted that the control of voltage in the droop control includes |V|-P droop control and |V|-Q droop control; the meaning of |V|-P droop control is to maintain the output voltage of the inverter within a certain range by controlling the active power of the inverter; the meaning of |V|-Q droop control is to maintain the voltage stability of the output end of the inverter by controlling the reactive power.

[0099] It should be further noted that, and are known quantities.

[0100] S5, constructing an extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equation of all nodes in the active power distribution network.

[0101] In a preferred embodiment, the step of constructing an extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equation of all nodes in the active power distribution network comprises:

[0102] constructing an initial extended Jacobian matrix according to the full Jacobian matrix and a preset reference node;

[0103] constructing an extended Jacobian matrix according to the initial extended Jacobian matrix and the inverter droop control mode equation of all nodes in the active power distribution network;

[0104] wherein the expression of the initial extended Jacobian matrix is:

[0105] In the formula, J E0 represents the initial extended Jacobian matrix; H E0 , N E0 , M E0 and L E0 represent block matrices, if node k is a reference node, then H E0 is the matrix obtained by deleting the kth row and the kth column of H f ; N E0 is the matrix obtained by deleting the kth row and the kth column of H f ; M E0 is the matrix obtained by deleting the kth row and the kth column of H f ; and L E0 is the matrix obtained by deleting the kth row and the kth column of Hf the matrix after deleting the kth row and the kth column;

[0106] The expression of the extended Jacobian matrix is:

[0107] The expression of the diagonal element of the extended Jacobian matrix is:

[0108] The expression of the non-diagonal element of the extended Jacobian matrix is:

[0109] wherein, J E represents the extended Jacobian matrix; H E , N E , M E and L E represent the block matrix.

[0110] It should be noted that the reference node is selected from the node connected with the upper power grid.

[0111] S6, substituting the operation data of each node in the active power distribution network into the extended Jacobian matrix, and calculating the minimum eigenvalue of the extended Jacobian matrix.

[0112] S7, judging whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue.

[0113] In a preferred embodiment, the judging whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue comprises:

[0114] judging whether the minimum eigenvalue is greater than zero; if yes, judging that the static voltage of the active power distribution network is stable; otherwise, judging that the static voltage of the active power distribution network is unstable.

[0115] In a preferred embodiment, after judging whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue, the method further comprises:

[0116] taking the real part of the minimum eigenvalue as a voltage stability margin index, and regulating and controlling the active power distribution network.

[0117] Embodiment two

[0118] Please refer to FIG. 2, which is a structural schematic diagram of a static voltage stability evaluation device provided by an embodiment of the present application, comprising a data information acquisition module, a full Jacobian matrix construction module, an inverter droop control mode equation construction module, an extended Jacobian matrix construction module and a static voltage stability evaluation module.

[0119] The data information acquisition module is configured to acquire operation data of each node in the active power distribution network and connection relationships between all nodes, wherein the operation data comprises voltage amplitude and phase angle.

[0120] The full Jacobian matrix construction module is configured to, for each node in the active power distribution network, construct an active power equation and a reactive power equation of the node according to the connection relationships, and construct a full Jacobian matrix of the active power distribution network according to the active power equations and the reactive power equations of all nodes in the active power distribution network.

[0121] The inverter droop control mode equation construction module is configured to, for each node in the active power distribution network, construct an inverter droop control mode equation of the node.

[0122] The extended Jacobian matrix construction module is configured to construct an extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equations of all nodes in the active power distribution network.

[0123] The static voltage stability evaluation module is configured to substitute the operation data of each node in the active power distribution network into the extended Jacobian matrix, calculate a minimum eigenvalue of the extended Jacobian matrix, and determine whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue.

[0124] Embodiment three

[0125] Correspondingly, an embodiment of the present application provides a terminal device, which comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and the processor implements the static voltage stability evaluation method in the above-mentioned embodiments of the application when executing the computer program.

[0126] Embodiment four

[0127] Correspondingly, an embodiment of the present application provides a storage medium, which comprises a stored computer program, wherein the computer program controls a device where the storage medium is located to execute the static voltage stability evaluation method in the above-mentioned embodiments of the application when running.

[0128] It should be noted that the apparatus embodiments described above are merely illustrative, and the units described as separate units can or can not be physically separate, and the units shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment according to actual needs. In addition, the connection between the modules in the apparatus embodiment provided by the present application indicates that there is a communication connection between them, which can be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creative labor.

[0129] Those skilled in the art can clearly understand that, for the convenience and brevity, the specific working process of the apparatus described above can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0130] The terminal device can be a desktop computer, a notebook computer, a palm computer, a cloud server and other computing devices. The terminal device can include, but is not limited to, a processor and a memory.

[0131] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc. The processor is the control center of the device, and connects various parts of the device through various interfaces and lines.

[0132] The memory can be used to store the computer program, and the processor realizes various functions of the device by running or executing the computer program stored in the memory and calling data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function, and the like; and the data storage area can store data created according to the use of the mobile phone and the like. In addition, the memory can include a high-speed random access memory, and can also include a nonvolatile memory, for example, a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other volatile solid-state memory devices.

[0133] The storage medium is a storage medium, and the computer program is stored in the storage medium. When the processor executes the computer program, the steps of each method embodiment described above can be realized. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the content included in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0134] The above is the preferred embodiment of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which are also considered within the scope of protection of the present application.

Claims

1. A static voltage stability assessment method, characterized by, The method comprises the following steps: obtaining the operation data of each node in the active power distribution network and the connection relationship between all nodes; wherein the operation data comprises voltage amplitude and phase angle; for each node in the active power distribution network, constructing the active power equation and the reactive power equation of the node according to the connection relationship; constructing the full Jacobian matrix of the active power distribution network according to the active power equation and the reactive power equation of all nodes in the active power distribution network; for each node in the active power distribution network, constructing the inverter droop control mode equation of the node; constructing the extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equation of all nodes in the active power distribution network; substituting the operation data of each node in the active power distribution network into the extended Jacobian matrix, and calculating the minimum eigenvalue of the extended Jacobian matrix; determining whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue.

2. The static voltage stability assessment method of claim 1, wherein, The step of constructing the active power equation and the reactive power equation of the node according to the connection relationship comprises the following steps: determining a plurality of adjacent nodes of the node according to the connection relationship; constructing the active power equation and the reactive power equation of the node according to the node and all adjacent nodes; wherein the expression of the active power equation is: The expression of the reactive power equation is: where ΔP i represents the injected active power variation of node i; representing the power injection of active power by the node i; PQ(i) represents the active power load at node i; AQ i ΔQ(i) represents the change in injected reactive power at node i; represents the power supply of node i injecting reactive power; represents the load reactive power of node i; U i represents the voltage amplitude of node i; U j represents the voltage amplitude of node j; j e i represents the nodes connected to node i; θ ij represents the phase angle between node i and node j; G ij represents the real part of admittance between node i and node j; B ij represents the imaginary part of admittance between node i and node j.

3. The static voltage stability assessment method of claim 2, wherein, The expression of the full Jacobian matrix is: wherein the expression of the diagonal elements of the full Jacobian matrix is: The off-diagonal elements of the full Jacobian matrix are expressed as: where J f represents the full Jacobian matrix; n is the number of PV nodes in the active distribution network; r is the number of PQ nodes in the active distribution network; H f , N f , M f and L f represent the block matrices; G ii is the real part of the self-admittance of node i; and B ii is the imaginary part of the self-admittance of node i.

4. The static voltage stability assessment method of claim 3, wherein, The step of constructing the inverter droop control mode equation of the node comprises the following steps: constructing the inverter droop control mode equation of the node considering the |V|-P droop control and the |V|-Q droop control; In the expression of the inverter droop control mode equation, the expression is as follows: The expression of the dynamic characteristics of the |V| -P droop control is: The expression of the dynamic characteristic of the |V| - Q droop control is: In the formulae, for the positive droop active coefficient of the generator on node i; for the positive droop reactive coefficient of the generator on node i; The reference voltage amplitude for node i; This represents the reference active power of the generator at node i when the voltage amplitude is the reference voltage amplitude. Qrefi = - (Vrefi - Vref) / Xs Pmin(i) = min{Pmin(i, j) for j in N(i)} Let be the maximum active power of the generator at node i; Let be the minimum reactive power of the generator at node i; the maximum reactive power of the generator on the node i.

5. The static voltage stability assessment method of claim 4, wherein, The step of constructing the extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equation of all nodes in the active power distribution network comprises the following steps: constructing an initial extended Jacobian matrix according to the full Jacobian matrix and a preset reference node; constructing the extended Jacobian matrix according to the initial extended Jacobian matrix and the inverter droop control mode equation of all nodes in the active power distribution network; wherein the expression of the initial extended Jacobian matrix is: where J E0 represents the initial extended Jacobian matrix; H E0 , N E0 , M E0 and L E0 represent block matrices, if node k is a reference node, then H E0 is the matrix Hfwith the k-th row and column removed, N E0 is the matrix Hfwith the k-th row and column removed, M E0 is the matrix Hfwith the k-th row and column removed, L E0 is the matrix Hfwith the k-th row and column removed; The expression of the extended Jacobian matrix is: The expression of the diagonal elements of the extended Jacobian matrix is: The expression of the off-diagonal elements of the extended Jacobian matrix is: where J E represents the extended Jacobian matrix; H E , N E , M E and L E represent block matrices.

6. The static voltage stability assessment method of claim 5, wherein, The step of determining whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue comprises the following steps: determining whether the minimum eigenvalue is greater than zero; if yes, determining that the static voltage of the active power distribution network is stable; otherwise, determining that the static voltage of the active power distribution network is unstable.

7. The static voltage stability assessment method of claim 6, wherein, After determining whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue, the method further comprises the following step: taking the real part of the minimum eigenvalue as a voltage stability margin index to regulate and control the active power distribution network.

8. A static voltage stability assessment device, characterized by, The method comprises the following steps: data information acquisition module, full Jacobian matrix construction module, inverter droop control mode equation construction module, extended Jacobian matrix construction module and static voltage stability evaluation module; the data information acquisition module is used for obtaining the operation data of each node in the active power distribution network and the connection relationship between all nodes; wherein the operation data comprises voltage amplitude and phase angle; the full Jacobian matrix construction module is used for constructing the active power equation and the reactive power equation of the node according to the connection relationship for each node in the active power distribution network; and constructing the full Jacobian matrix of the active power distribution network according to the active power equation and the reactive power equation of all nodes in the active power distribution network. The inverter droop control mode equation construction module is configured to construct an inverter droop control mode equation of each node in the active power distribution network. The extended Jacobian matrix construction module is configured to construct an extended Jacobian matrix according to the full Jacobian matrix and the inverter droop control mode equations of all nodes in the active power distribution network. The static voltage stability evaluation module is configured to substitute the operating data of each node in the active power distribution network into the extended Jacobian matrix, calculate a minimum eigenvalue of the extended Jacobian matrix, and determine whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue.

9. A terminal device, comprising: The storage medium includes a stored computer program, wherein the computer program controls a device in which the storage medium is located to perform the static voltage stability evaluation method according to any one of claims 1 to 7 when the computer program is executed.

10. A storage medium, characterized by The storage medium includes a stored computer program, wherein the computer program controls a device in which the storage medium is located to perform the static voltage stability evaluation method according to any one of claims 1 to 7 when the computer program is executed.

Images