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

Abstract

The invention discloses a static voltage stability evaluation method and device, terminal equipment and a storage medium. The method comprises the following steps: acquiring operation data of nodes in an active power distribution network and a connection relationship among all the nodes; constructing a full Jacobian matrix of the active power distribution network and an inverter droop control mode equation; further constructing an extended Jacobian matrix; then obtaining operation data of the nodes, and calculating a minimum characteristic value of the extended Jacobian matrix according to the operation data; and carrying out static voltage stability evaluation according to the minimum characteristic value. According to the method, the dynamic characteristics of the control mode of the new energy grid-connected inverter are fully considered during static voltage stability evaluation, the accuracy of static stability evaluation of the active power distribution network under new energy grid connection is improved, and a guarantee is provided for static stable operation of the active power distribution network.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a static voltage stability assessment method, device, terminal equipment and storage medium. Background Art

[0002] The development of a high-proportion renewable energy power system is the general trend of the future power system, but the access of a high proportion of renewable energy will bring many problems and challenges to the power grid, among which the problems caused by renewable energy to the static stable operation of the power grid are particularly prominent. First, a high proportion of renewable energy will introduce a high proportion of power electronic devices. The "double high" characteristics of the power system will change the static voltage stability mechanism and even further complicate it, which may lead to the failure of traditional stability analysis. Secondly, due to the fluctuating and random characteristics of renewable energy output and the volatility of load, a high proportion of renewable energy power system is prone to source-load imbalance, affecting the static stable operation of the power grid. In addition, the limited active regulation of energy and the lack of dynamic reactive power support capabilities will cause a decrease in voltage stability and even cause large-scale new energy collective disconnection accidents. Therefore, it is extremely important to achieve reliable and efficient active distribution network static voltage stability assessment to ensure the static stable operation of the power grid.

[0003] Traditional static voltage stability assessment methods are already quite mature. The current static voltage stability assessment methods after new energy grid connection are obtained by modifying the traditional methods based on the output characteristics and dynamics of new energy. However, in fact, the grid-connected inverter control mode has a significant impact on the system voltage stability margin, but the existing distribution network static voltage stability assessment method does not fully consider the dynamic characteristics of the new energy grid-connected inverter control mode. Therefore, it is necessary to study the static voltage assessment problem under the inverter control mode to better achieve the stable control of the static voltage of the distribution network under the grid connection of the energy system. Summary of the invention

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

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a static voltage stability evaluation method, comprising:

[0006] Acquire 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 power distribution network, constructing an active power equation and a reactive power equation of the node according to the connection relationship;

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

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

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

[0011] Substituting the operating 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;

[0012] Whether the static voltage of the active power distribution network is stable is judged according to the minimum characteristic value.

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

[0014] Determine a number of adjacent nodes of the node according to the connection relationship;

[0015] Constructing an active power equation and a 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]

[0018] The expression of the reactive power equation is:

[0019]

[0020] In the formula, ΔP i represents the change in injected active power of node i; represents the active power injected by the power supply of node i; represents the load active power of node i; ΔQ i represents the change in injected reactive power of node i; represents the reactive power injected by the power source of node i; represents the reactive power of the load at node i; U i represents the voltage amplitude of node i; U j represents the voltage amplitude of node j; j∈i represents the node j connected to node i; θ ij represents the phase angle between node i and node j; G ij is the real part of the admittance between node i and node j; B ijis the imaginary part of the admittance between nodes i and j.

[0021] As a preferred solution, the expression of the full Jacobian matrix is:

[0022]

[0023] Among them, the expression of the diagonal element of the full Jacobian matrix is:

[0024]

[0025] The expression of the off-diagonal elements of the full Jacobian matrix is:

[0026]

[0027] In the formula, 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 represents the block matrix; 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.

[0028] As a preferred solution, the inverter droop control mode equation of the node is constructed, including:

[0029] Constructing an inverter droop control mode equation considering -droop control and -droop control for the node;

[0030] The expression of the inverter droop control mode equation is:

[0031]

[0032] The expression of the dynamic characteristics of |V|-P droop control is:

[0033]

[0034] The expression of |V|-Q droop control dynamic characteristics is:

[0035]

[0036] In the formula, k pi is the positive droop active coefficient of the generator at node i; k qi is the positive droop reactive power 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; is the reference reactive power of the generator at node i when the voltage amplitude is the reference voltage amplitude; is the minimum active power of the generator at node i; is the maximum active power of the generator at node i; is the minimum reactive power of the generator at node i; is the maximum reactive power of the generator at node i.

[0037] As a preferred solution, the extended Jacobian matrix is ​​constructed according to the full Jacobian matrix and the inverter droop control mode equations of all nodes in the active power distribution network, including:

[0038] Constructing an initial extended Jacobian matrix according to the full Jacobian matrix and the preset reference nodes;

[0039] constructing an extended Jacobian matrix according to the initial extended Jacobian matrix and inverter droop control mode equations of all nodes in the active distribution network;

[0040] Wherein, the expression of the initial extended Jacobian matrix is:

[0041]

[0042] In the formula, J E0 represents the initial expanded Jacobian matrix; H E0 、N E0 、M E0 and L E0 represents the block matrix. If node k is the reference node, then H E0 H f The matrix after deleting the kth row and kth column, N E0 H f The matrix after deleting the kth row and kth column, M E0 H f The matrix after deleting the kth row and kth column, L E0 H f The matrix after deleting the k-th row and k-th column;

[0043] The expression of the extended Jacobian matrix is:

[0044]

[0045] The expression of the diagonal elements of the extended Jacobian matrix is:

[0046]

[0047] The expression of the off-diagonal elements of the extended Jacobian matrix is:

[0048]

[0049] In the formula, J E represents the extended Jacobian matrix; H E 、N E 、M E and L E Represents a block matrix.

[0050] As a preferred solution, judging whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue includes:

[0051] It is determined whether the minimum eigenvalue is greater than zero; if so, it is determined that the static voltage of the active power distribution network is stable; otherwise, it is determined that the static voltage of the active power distribution network is unstable.

[0052] As a preferred solution, after judging whether the static voltage of the active power distribution network is stable according to the minimum characteristic value, the method further includes:

[0053] The real part of the minimum eigenvalue is used as a voltage stability margin indicator to regulate the active distribution network.

[0054] Based on the above embodiment, another embodiment of the present invention provides a static voltage stability assessment device, including: 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 assessment module;

[0055] The data information acquisition module is used to obtain the operating data of each node in the active power distribution network and the connection relationship between all nodes; wherein the operating data includes voltage amplitude and phase angle;

[0056] The full Jacobian matrix construction module is used to construct the active power equation and reactive power equation of each node in the active distribution network according to the connection relationship; and to construct the full Jacobian matrix of the active distribution network according to the active power equation and reactive power equation of all nodes in the active distribution network;

[0057] The inverter droop control mode equation building module is used to build the inverter droop control mode equation of each node in the active power distribution network;

[0058] The extended Jacobian matrix construction module is used 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;

[0059] The static voltage stability evaluation module is used to substitute the operating data of each node in the active distribution network into the extended Jacobian matrix and calculate the minimum eigenvalue of the extended Jacobian matrix; and judge whether the static voltage of the active distribution network is stable according to the minimum eigenvalue.

[0060] Based on the above embodiments, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, the static voltage stability evaluation method described in the above invention embodiments is implemented.

[0061] Based on the above embodiments, another embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the static voltage stability evaluation method described in the above invention embodiment.

[0062] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0063] The present invention obtains the equipment data and connection relationship of the nodes in the active distribution network; constructs the full Jacobian matrix and inverter droop control mode equation of the active distribution network; further constructs the extended Jacobian matrix; then obtains the operation data of the node, 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. When performing static voltage stability evaluation, the present invention fully considers the dynamic characteristics of the control mode of the inverter connected to the grid of new energy, improves the accuracy of the static stability evaluation of the active distribution network under the grid connection of new energy, and provides a guarantee for the static stable operation of the active distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a flow chart of a static voltage stability evaluation method provided by an embodiment of the present invention;

[0065] Figure 2 It is a structural schematic diagram of a static voltage stability evaluation device provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0068] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0069] 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.

[0070] Embodiment 1

[0071] Please refer to Figure 1 , is a flow chart of a static voltage stability evaluation method provided by an embodiment of the present invention, comprising:

[0072] S1. Obtaining the operating data of each node in the active distribution network and the connection relationship between all nodes; wherein the operating data includes voltage amplitude and phase angle.

[0073] It should be noted that the evaluation object of the static voltage stability evaluation method provided by the present invention is the static voltage of an active distribution network including a grid-connected inverter.

[0074] In this embodiment, the voltage amplitude and phase angle of each node in the active power distribution network are obtained by a synchronous phasor measurement device.

[0075] S2. 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 relationship.

[0076] It should be noted that the power flow equation and power equation of the power system are expressed as follows:

[0077]

[0078] In the formula, represents the injected complex power of node i, represents the change in the injected complex power of node i, represents the given value of the complex power injected into node i, represents the calculated value of the complex power injected into node i.

[0079]

[0080] In the formula, represents the power injected by the node’s power supply, Indicates the load power of the node.

[0081]

[0082] In the formula, represents the voltage of the node, represents the conjugate of the injected current at the node.

[0083]

[0084] The above formula is the calculation formula for node injection current, where: is the node current vector, Y is the system admittance matrix, is the node voltage vector.

[0085] In the following embodiment, according to the connection relationship, several adjacent nodes of the node are determined, the flow equation and power equation of the above-mentioned power system are combined, and the part involving active power and the part involving reactive power are written separately to obtain the active power equation and reactive power equation of the node.

[0086] In a preferred embodiment, constructing the active power equation and the reactive power equation of the node according to the connection relationship includes:

[0087] Determine a number of adjacent nodes of the node according to the connection relationship;

[0088] Constructing an active power equation and a reactive power equation of the node according to the device data of the node and all the adjacent nodes;

[0089] Wherein, the expression of the active power equation is:

[0090]

[0091] The expression of the reactive power equation is:

[0092]

[0093] In the formula, ΔP i represents the change in injected active power of node i; represents the active power injected by the power supply of node i; represents the load active power of node i; ΔQ i represents the change in injected reactive power of node i; represents the reactive power injected by the power source of node i; represents the reactive power of the load at node i; U i represents the voltage amplitude of node i; U j represents the voltage amplitude of node j; j∈i represents the node j connected to node i; θ ij represents the phase angle between node i and node j; G ij is the real part of the admittance between node i and node j; B ij is the imaginary part of the admittance between nodes i and j.

[0094] It should be noted that G ij and B ij is a known quantity.

[0095] S3. Constructing a full Jacobian matrix of the active distribution network according to the active power equations and reactive power equations of all nodes in the active distribution network.

[0096] It should be noted that this method is applicable to a power system containing a balancing node, several PV nodes and several PQ nodes.

[0097] In a preferred embodiment, the expression of the full Jacobian matrix is:

[0098]

[0099] Among them, the expression of the diagonal element of the full Jacobian matrix is:

[0100]

[0101] The expression of the off-diagonal elements of the full Jacobian matrix is:

[0102]

[0103] In the formula, 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 represents the block matrix; 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.

[0104] It should be noted that the full Jacobian matrix of this method is derived from the simplified Jacobian matrix. The following is the derivation process of the full Jacobian matrix:

[0105] It is known that the expression of the simplified Jacobian matrix of the static equation of the power system is:

[0106]

[0107] Where 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 of The block matrix representation of The block matrix representation of The block matrix representation of .

[0108] For PQ nodes, is a given constant. For the PV node, is a given constant, then Therefore, we have:

[0109]

[0110] That is, the complex power variation injected at this time is The first-order partial derivatives of the voltage amplitude and phase angle are calculated as the injected complex power. The first-order partial derivative of , then the expression of the diagonal element of the simplified Jacobian matrix J is:

[0111]

[0112] The expression of the off-diagonal elements of the simplified Jacobian matrix J is:

[0113]

[0114] The full Jacobian matrix is ​​the Jacobian matrix that takes into account the active power equation and reactive power equation 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 above full Jacobian matrix. The calculation method of the off-diagonal elements of each block of the full Jacobian matrix is ​​the same as the calculation method of the off-diagonal elements of the simplified Jacobian matrix.

[0115] It should also be 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 is a known quantity.

[0116] S4. For each node in the active power distribution network, construct an inverter droop control mode equation of the node.

[0117] In a preferred embodiment, constructing the inverter droop control mode equation of the node according to the device data includes:

[0118] According to the device data, construct an inverter droop control mode equation for the node considering |V|-P droop control and |V|-Q droop control;

[0119] The expression of the inverter droop control mode equation is:

[0120]

[0121] The expression of the dynamic characteristics of |V|-P droop control is:

[0122]

[0123] The expression of |V|-Q droop control dynamic characteristics is:

[0124]

[0125] In the formula, is the positive droop active power coefficient of the generator at node i; is the positive droop reactive power 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; is the reference reactive power of the generator at node i when the voltage amplitude is the reference voltage amplitude; is the minimum active power of the generator at node i; is the maximum active power of the generator at node i; is the minimum reactive power of the generator at node i; is the maximum reactive power of the generator at node i.

[0126] It should be noted that the voltage control in droop control includes |V|-P droop control and |V|-Q droop control; among them, |V|-P droop control means controlling the active power of the inverter to ensure that the inverter output voltage is maintained within a certain range; |V|-Q droop control means maintaining the voltage stability at the inverter output end by controlling the reactive power.

[0127] It should also be noted that and All are known quantities.

[0128] S5. 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.

[0129] In a preferred embodiment, the extended Jacobian matrix is ​​constructed according to the full Jacobian matrix and the inverter droop control mode equations of all nodes in the active power distribution network, including:

[0130] Constructing an initial extended Jacobian matrix according to the full Jacobian matrix and the preset reference nodes;

[0131] constructing an extended Jacobian matrix according to the initial extended Jacobian matrix and inverter droop control mode equations of all nodes in the active distribution network;

[0132] Wherein, the expression of the initial extended Jacobian matrix is:

[0133]

[0134] In the formula, J E0 represents the initial expanded Jacobian matrix; H E0 、N E0 、M E0 and L E0 represents the block matrix. If node k is the reference node, then H E0 H f The matrix after deleting the kth row and kth column, N E0 H f The matrix after deleting the kth row and kth column, M E0 H f The matrix after deleting the kth row and kth column, L E0 H f The matrix after deleting the k-th row and k-th column;

[0135] The expression of the extended Jacobian matrix is:

[0136]

[0137] The expression of the diagonal elements of the extended Jacobian matrix is:

[0138]

[0139]

[0140] The expression of the off-diagonal elements of the extended Jacobian matrix is:

[0141]

[0142] In the formula, J E represents the extended Jacobian matrix; HE 、N E 、M E and L E Represents a block matrix.

[0143] It should be noted that the reference node is a node connected to the upper-level power grid.

[0144] S6. Substitute the operating data of each node in the active power distribution network into the extended Jacobian matrix, and calculate the minimum eigenvalue of the extended Jacobian matrix.

[0145] S7. Determine whether the static voltage of the active power distribution network is stable according to the minimum eigenvalue.

[0146] In a preferred embodiment, judging whether the static voltage of the active power distribution network is stable according to the minimum characteristic value includes:

[0147] It is determined whether the minimum eigenvalue is greater than zero; if so, it is determined that the static voltage of the active power distribution network is stable; otherwise, it is determined that the static voltage of the active power distribution network is unstable.

[0148] In a preferred embodiment, after judging whether the static voltage of the active power distribution network is stable according to the minimum characteristic value, the method further includes:

[0149] The real part of the minimum eigenvalue is used as a voltage stability margin indicator to regulate the active distribution network.

[0150] Embodiment 2

[0151] Please refer to Figure 2 , is a schematic diagram of the structure of a static voltage stability assessment device provided by an embodiment of the present invention, 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 assessment module;

[0152] The data information acquisition module is used to obtain the operating data of each node in the active power distribution network and the connection relationship between all nodes; wherein the operating data includes voltage amplitude and phase angle;

[0153] The full Jacobian matrix construction module is used to construct the active power equation and reactive power equation of each node in the active distribution network according to the connection relationship; and to construct the full Jacobian matrix of the active distribution network according to the active power equation and reactive power equation of all nodes in the active distribution network;

[0154] The inverter droop control mode equation building module is used to build the inverter droop control mode equation of each node in the active power distribution network;

[0155] The extended Jacobian matrix construction module is used 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;

[0156] The static voltage stability evaluation module is used to substitute the operating data of each node in the active distribution network into the extended Jacobian matrix and calculate the minimum eigenvalue of the extended Jacobian matrix; and judge whether the static voltage of the active distribution network is stable according to the minimum eigenvalue.

[0157] Embodiment 3

[0158] Accordingly, an embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, the static voltage stability assessment method described in the above-mentioned embodiment of the invention is implemented.

[0159] Embodiment 4

[0160] Accordingly, an embodiment of the present invention provides a storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the storage medium is located is controlled to execute the static voltage stability evaluation method described in the above embodiment of the invention.

[0161] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0162] Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0163] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0164] The processor may be a central processing unit (CPU), or 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. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the device, and various interfaces and lines are used to connect various parts of the entire device.

[0165] 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 the 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 for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (FlashCard), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0166] The storage medium is a storage medium, and the computer program is stored in the storage medium. When the computer program is executed by the processor, the steps of each method embodiment described above can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained 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, computer readable media do not include electric carrier signals and telecommunication signals.

[0167] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A static voltage stability evaluation method, characterized in that: include: Acquire 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; For each node in the active power distribution network, constructing an active power equation and a reactive power equation of the node according to the connection relationship; Constructing a full Jacobian matrix of the active distribution network according to the active power equations and reactive power equations of all nodes in the active distribution network; For each node in the active power distribution network, construct an inverter droop control mode equation of the node; constructing an extended Jacobian matrix according to the full Jacobian matrix and inverter droop control mode equations of all nodes in the active distribution network; Substituting the operating 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; Whether the static voltage of the active power distribution network is stable is judged according to the minimum characteristic value.

2. The static voltage stability evaluation method according to claim 1, characterized in that: The constructing the active power equation and the reactive power equation of the node according to the connection relationship includes: Determine a number of adjacent nodes of the node according to the connection relationship; Constructing an active power equation and a reactive power equation of the node according to the node and all the adjacent nodes; Wherein, the expression of the active power equation is: The expression of the reactive power equation is: Where ΔP i represents the change in injected active power of node i; represents the active power injected by the power supply of node i; represents the load active power of node i; ΔQ i represents the change in injected reactive power of node i; represents the reactive power injected by the power source of node i; represents the reactive power of the load at node i; U i represents the voltage amplitude of node i; U j represents the voltage amplitude of node j; j∈i represents the node j connected to node i; θ ij represents the phase angle between node i and node j; G ij is the real part of the admittance between node i and node j; B ij is the imaginary part of the admittance between nodes i and j.

3. The static voltage stability evaluation method according to claim 2, characterized in that: The expression of the full Jacobian matrix is: Among them, the expression of the diagonal element of the full Jacobian matrix is: The expression of the non-diagonal elements of the full Jacobian matrix is: In the formula, 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 represents the block matrix; 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.

4. The static voltage stability evaluation method according to claim 3, characterized in that: The step of constructing the inverter droop control mode equation of the node includes: Constructing an inverter droop control mode equation for the node considering |V|-P droop control and |V|-Q droop control; The expression of the inverter droop control mode equation is: The expression of |V|-P droop control dynamic characteristics is: The expression of |V|-Q droop control dynamic characteristics is: In the formula, is the positive droop active power coefficient of the generator at node i; is the positive droop reactive power 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; is the reference reactive power of the generator at node i when the voltage amplitude is the reference voltage amplitude; is the minimum active power of the generator at node i; is the maximum active power of the generator at node i; is the minimum reactive power of the generator at node i; is the maximum reactive power of the generator at node i.

5. The static voltage stability evaluation method according to claim 4, characterized in that: The step of constructing 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 includes: Constructing an initial extended Jacobian matrix according to the full Jacobian matrix and the preset reference nodes; constructing an extended Jacobian matrix according to the initial extended Jacobian matrix and inverter droop control mode equations of all nodes in the active distribution network; Wherein, the expression of the initial extended Jacobian matrix is: In the formula, J E0 represents the initial expanded Jacobian matrix; H E0 、N E0 、M E0 and L E0 represents the block matrix. If node k is the reference node, then H E0 H f The matrix after deleting the kth row and kth column, N E0 H f The matrix after deleting the kth row and kth column, M E0 H f The matrix after deleting the kth row and kth column, L E0 H f The matrix after deleting the k-th row and k-th column; 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: In the formula, J E represents the extended Jacobian matrix; H E 、N E 、M E and L E Represents a block matrix.

6. The static voltage stability evaluation method according to claim 5, characterized in that: The step of judging whether the static voltage of the active power distribution network is stable according to the minimum characteristic value includes: It is determined whether the minimum eigenvalue is greater than zero; if so, it is determined that the static voltage of the active power distribution network is stable; otherwise, it is determined that the static voltage of the active power distribution network is unstable.

7. The static voltage stability evaluation method according to claim 6, characterized in that: After judging whether the static voltage of the active power distribution network is stable according to the minimum characteristic value, the method further includes: The real part of the minimum eigenvalue is used as a voltage stability margin indicator to regulate the active distribution network.

8. A static voltage stability assessment device, characterized in that: include: Data information acquisition module, full Jacobian matrix building module, inverter droop control mode equation building module, extended Jacobian matrix building module and static voltage stability evaluation module; The data information acquisition module is used to obtain the operating data of each node in the active power distribution network and the connection relationship between all nodes; wherein the operating data includes voltage amplitude and phase angle; The full Jacobian matrix construction module is used to construct the active power equation and reactive power equation of each node in the active distribution network according to the connection relationship; and to construct the full Jacobian matrix of the active distribution network according to the active power equation and reactive power equation of all nodes in the active distribution network; The inverter droop control mode equation building module is used to build the inverter droop control mode equation of each node in the active power distribution network; The extended Jacobian matrix construction module is used 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 used to substitute the operating data of each node in the active distribution network into the extended Jacobian matrix and calculate the minimum eigenvalue of the extended Jacobian matrix; and judge whether the static voltage of the active distribution network is stable according to the minimum eigenvalue.

9. A terminal device, characterized in that: The method comprises 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 according to any one of claims 1 to 7 when executing the computer program.

10. A storage medium, characterized in that: The storage medium includes a stored computer program, wherein when the computer program is executed, the device where the storage medium is located is controlled to execute the static voltage stability evaluation method according to any one of claims 1 to 7.

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