A method and device for transient simulation of power system based on virtual admittance

Abstract

The present application provides a method for transient simulation of a power system based on virtual admittance, comprising: obtaining the node voltage and phase angle value of each dynamic element in the power system to be simulated at the current moment; calculating the node injection current of each dynamic element based on the node voltage and phase angle value of each dynamic element, and calculating the virtual admittance matrix of each dynamic element according to the node voltage and node injection current of each dynamic element; using the virtual admittance matrix to correct the network equation of the current time step to obtain a new network equation; using the new network equation to perform transient simulation of the power system at the current time step until the simulation convergence condition is met. The simulation method proposed in the present invention uses a virtual admittance matrix to correct the network equation of the system, thereby improving the convergence of transient simulation. In particular, for systems with new energy grid connection, it can achieve equivalent transformation of the whole system simulation model with the goal of improving convergence, thereby solving the problem of non-convergence of simulation.

Description

Technical Field

[0001] The present invention relates to power system simulation technology, and in particular to a power system transient simulation method and device based on virtual admittance. Background Art

[0002] With the development of new power systems, more and more renewable energy sources such as wind power and photovoltaics are being connected to the grid. As the proportion of renewable energy in the system increases, the system is increasingly showing characteristics such as strong randomness in operation, low system inertia, and weak voltage support due to the natural properties of renewable energy units such as randomness, volatility, and weak support. This leads to a decrease in the system's anti-disturbance ability and a wide range of fault impacts. Therefore, it is particularly important to analyze the operating status of the power system through time domain simulation.

[0003] In traditional simulation algorithms, the mathematical models of each dynamic component can be explicitly represented through a system of differential algebraic equations. Therefore, the convergence of the simulation can be improved by performing equivalent transformations on the component mathematical model equations. However, for new energy equipment such as wind power and photovoltaics, since their control strategies and structural designs are the manufacturer's trade secrets, power grid companies cannot directly obtain the explicit mathematical models of these new energy equipment. Instead, they can obtain a packaged model of the new energy equipment, which is generally a compiled and encrypted DLL model. As the scale of power systems continues to expand, the rigidity of the full system model continues to increase. Since the packaged models provided by manufacturers cannot be used to transform the system model through explicit changes, the convergence of system time-domain simulations is becoming increasingly common.

[0004] Therefore, in the context of large-scale renewable energy grid connection, how to solve the algorithm convergence problem of integrating a large number of packaged models in the system during time domain simulation is an issue worthy of in-depth study. Summary of the Invention

[0005] Based on this, the present invention aims to propose a method and device for transient simulation of power systems based on virtual admittance. For systems containing new energy, the virtual admittance of the package model of each dynamic element is calculated to correct the network equations of the system, thereby improving the convergence of time domain simulation.

[0006] In a first aspect, the present invention proposes a power system transient simulation method based on virtual admittance, comprising:

[0007] Obtaining the node voltage and phase angle values of each dynamic element in the power system to be simulated at the current moment;

[0008] Calculating the node injection current of each dynamic element based on the node voltage and phase angle value of each dynamic element, and calculating the virtual admittance matrix of each dynamic element according to the node voltage and node injection current of each dynamic element;

[0009] Use the virtual admittance matrix to modify the network equation of the current time step and obtain a new network equation;

[0010] The new network equations are used to perform transient simulation of the power system at the current time step until the simulation convergence conditions are met.

[0011] Furthermore, calculating the node injection current of each dynamic element based on the node voltage and phase angle value of each dynamic element includes:

[0012] The node voltage is vector decomposed using the phase angle value to obtain the voltage components;

[0013] A disturbance value is set for the voltage component, and the voltage component and the disturbance value are input into the dynamic model of the dynamic element for calculation to obtain the node injection current component corresponding to each voltage component.

[0014] Furthermore, the voltage components obtained by vector decomposing the node voltage using the phase angle value include:

[0015] The node voltage is vector-decomposed on the x-axis and y-axis using the phase angle value. The specific decomposition is as follows:

[0016]

[0017] in, and Represents the node voltage The x-axis and y-axis components of Indicates the phase angle value.

[0018] Furthermore, the disturbance amount is set for each voltage component, and the voltage component and the disturbance amount are input into the dynamic model of the dynamic element for calculation. The node injection current components corresponding to each voltage component are obtained, including:

[0019] The voltage component is analyzed based on the linear sensitivity method and Set the disturbance amount separately and ;

[0020] The voltage component and Input the dynamic model of the dynamic element to obtain the injected current and ;

[0021] Apply a disturbance in the x-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the first node injection current component ;

[0022] Apply a disturbance in the y-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the second node injection current component .

[0023] Furthermore, calculating the virtual admittance matrix of each dynamic element according to the node voltage and node injection current of each dynamic element includes:

[0024] The following system of equations is constructed using the voltage components and the node injection current components:

[0025]

[0026]

[0027] Solve the equations to get the virtual admittance matrix of each dynamic element .

[0028] Furthermore, the network equations for the current time step are corrected using the virtual admittance matrix, including:

[0029] The virtual admittance matrices of all dynamic elements in the power system are formed into diagonal block matrices;

[0030] Use the diagonal block matrix to calculate the initial network equation according to the following relationship Correction:

[0031]

[0032] Solve the above equations for , we get the new network equation, where represents the network admittance matrix of the power system, represents the node voltage vector, represents the node injection current vector, Representing the diagonal block matrix composed of the virtual admittance matrices of all dynamic elements, it has the following expression:

[0033]

[0034] Where n represents the number of dynamic elements in the power system, Represents the virtual admittance matrix of the nth dynamic element.

[0035] Furthermore, in the transient simulation of the power system, the simulation convergence conditions for each time step include:

[0036]

[0037] Where k represents the number of iterations per time step, and represent the node voltages at the kth and k-1th iterations in the same time step, Indicates the convergence threshold.

[0038] In a second aspect, the present invention provides a power system transient simulation device based on virtual admittance, comprising:

[0039] A data acquisition module is used to obtain the node voltage and phase angle value of each dynamic element in the power system to be simulated at the current moment;

[0040] The virtual admittance calculation module is used to perform the virtual admittance matrix calculation process in the first iteration calculation of the current time step. The virtual admittance matrix calculation process includes:

[0041] Calculating the node injection current of each dynamic element based on the node voltage and phase angle value of each dynamic element, and calculating the virtual admittance matrix of each dynamic element according to the node voltage and node injection current of each dynamic element;

[0042] The network equation correction module is used to correct the network equation of the current time step using the virtual admittance matrix;

[0043] The transient simulation module is used to perform transient simulation of the power system at the current time step using the network equations until the simulation convergence conditions are met.

[0044] In a third aspect, the present invention provides an electronic device comprising a memory storing computer-executable instructions and a processor, wherein when the computer-executable instructions are executed by the processor, the device executes the various steps of the power system transient simulation method based on virtual admittance provided in the first aspect.

[0045] In a fourth aspect, the present invention provides a readable storage medium storing a computer executable program, which, when executed, can implement the various steps of the power system transient simulation method based on virtual admittance provided in the first aspect.

[0046] It can be seen from the above technical solutions that the present invention has the following beneficial effects:

[0047] The present invention provides a power system transient simulation method based on virtual admittance. The corresponding virtual admittance matrix is calculated according to the node voltage and phase angle value of each dynamic element at the current moment. The network equation of the system is corrected using the virtual admittance matrix, thereby improving the convergence of the transient simulation. The virtual admittance matrix is used to simulate the real response of the dynamic elements, so that the system model can be equivalently transformed even in the absence of an explicit mathematical model of the element. In particular, for systems with new energy grid connection, the equivalent transformation of the whole system simulation model with the goal of improving convergence can be achieved, thereby solving the problem of simulation non-convergence. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0049] Figure 1 A flowchart of an implementation method of a power system transient simulation based on virtual admittance provided by one embodiment of the present invention;

[0050] Figure 2 A flowchart of an implementation method of a power system transient simulation based on virtual admittance provided by another embodiment of the present invention;

[0051] Figure 3 An electrical structure diagram of an improved IEEE-9 node system according to an embodiment of the present invention, wherein nodes 5 and 6 are connected to a wind farm and a photovoltaic power station, respectively;

[0052] Figure 4 for Figure 3 Schematic diagram of wind farm node voltage test results in the IEEE-9 node system;

[0053] Figure 5 for Figure 3 Schematic diagram of the voltage test results of photovoltaic power station nodes in the IEEE-9 node system;

[0054] Figure 6 for Figure 3 Schematic diagram of the node voltage test results of the synchronous generator connected to node 1 in the IEEE-9 node system;

[0055] Figure 7 for Figure 3 Schematic diagram of the iterative results of the node voltage at the wind farm grid connection point in the IEEE-9 node system in the first time step after the system fault;

[0056] Figure 8 for Figure 3 Schematic diagram of the iterative results of the node voltage at the grid connection point of a photovoltaic power station in the IEEE-9 node system in the first time step after a system fault;

[0057] Figure 9 A schematic structural diagram of a power system transient simulation device based on virtual admittance provided by an embodiment of the present invention;

[0058] Figure 10 This is a diagram of the electronic device architecture provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0060] Transient simulation of power systems simulates the dynamic response of power systems after disturbances (such as faults, load fluctuations, or equipment switching). It tracks the changes in the power system state over time by solving the system's differential algebraic equations. Simulations with good convergence can ensure that the equations are quickly and accurately solved during the iteration process of each time step. If the simulation does not converge, the system state may not be updated correctly, causing the simulation results to deviate from the actual situation and affecting decision-making.

[0061] However, the grid connection of renewable energy has a significant impact on the convergence of transient simulation of power systems, especially when a high proportion of renewable energy is connected to the grid. New energy equipment usually cannot be directly converted into explicit mathematical models, and its nonlinear characteristics and complex control strategies also aggravate the problem of difficulty in simulation convergence.

[0062] Based on this, an embodiment of the present invention proposes a power system transient simulation method based on virtual admittance. For systems containing new energy, the virtual admittance of the package model of each dynamic element is calculated to correct the network equation of the system, thereby improving the convergence of time domain simulation.

[0063] See Figure 1 One embodiment of the present invention provides a method for simulating power system transients based on virtual admittance, comprising the following steps:

[0064] Step S110: Obtain node voltages and phase angle values of each dynamic element in the power system to be simulated at the current moment.

[0065] Specifically, the node voltage and phase angle values of dynamic elements can be obtained by solving the system's power flow equation (i.e., the initial network equation of the power grid). Dynamic elements refer to devices with dynamic behavior that require differential equations or other time-dependent models to describe their transient response and long-term dynamic behavior. The states of these elements change over time and are usually used to analyze the system's response to disturbances, faults, or other dynamic conditions, including generators, loads, inverters, etc.

[0066] The power system is modeled by the node admittance matrix, which represents the electrical relationship between nodes. The initial network equation of the system can be expressed as ,in represents the node admittance matrix of the power system, represents the node voltage vector, represents the node injection current vector.

[0067] Step S120 . Calculate the node injection current of each dynamic element based on the node voltage and phase angle value of each dynamic element, and calculate the virtual admittance matrix of each dynamic element according to the node voltage and node injection current of each dynamic element.

[0068] During the simulation process, the virtual admittance matrix is dynamically adjusted at each time step based on the real-time state of the dynamic elements (such as node voltages and currents). Therefore, the virtual admittance matrix for each dynamic element is calculated during the first iteration of each simulation time step. It is not calculated again during subsequent iterations of the same time step until the first iteration of the next time step, when the virtual admittance matrix for each dynamic element is updated. The virtual admittance matrix is obtained by actively introducing virtual disturbances into the system to obtain the system's dynamic response and control characteristics. It does not represent the admittance of the actual physical circuit.

[0069] The node injection current of a dynamic element is determined by the relationship between the element's voltage and its impedance or admittance. Therefore, the dynamic model of each element is used to solve the injection current based on its node voltage and phase angle value and the power injected by the element. The virtual admittance matrix reflects the response of each dynamic element to voltage changes. Once the node voltage and injection current are known when a virtual disturbance is introduced, the corresponding virtual admittance can be obtained according to Ohm's law. The virtual admittance of each dynamic element is organized into a diagonal matrix, which is the virtual admittance matrix of the system.

[0070] In a further embodiment, when calculating the node injection current of a dynamic element, the node voltage is vector decomposed using the phase angle value to obtain voltage components, a disturbance value is set for the voltage component, and the voltage component and the disturbance value are input into the dynamic model of the dynamic element for calculation to obtain the node injection current components corresponding to each voltage component.

[0071] Step S130: Use the virtual admittance matrix to correct the network equation of the current time step to obtain a new network equation.

[0072] Specifically, the accuracy and convergence of transient simulation can be improved by introducing the nonlinear characteristics and control behaviors of dynamic elements into the network equations. The virtual admittance matrix is used to dynamically update the node admittance matrix of the power system, so that the system model can accurately reflect the instantaneous state changes of dynamic elements in the simulation at each time step.

[0073] In a further embodiment, step S130 includes the following steps:

[0074] The virtual admittance matrices of all dynamic elements in the power system are formed into diagonal block matrices;

[0075] Use the diagonal block matrix to calculate the initial network equation according to the following relationship Correction:

[0076]

[0077] Solve the above equations for , we get the new network equation, where represents the node admittance matrix of the power system, represents the node voltage vector, represents the node injection current vector, Representing the diagonal block matrix composed of the virtual admittance matrices of all dynamic elements, it has the following expression:

[0078]

[0079] Where n represents the number of dynamic elements in the power system, Represents the virtual admittance matrix of the nth dynamic element. For nodes in the system that have no dynamic elements connected, their virtual admittance is set to 0 matrix.

[0080] Step S140: Use the new network equations to perform power system transient simulation at the current time step until the simulation convergence condition is met.

[0081] Specifically, during each iterative calculation, the injected current of each dynamic component is calculated based on the control strategy of the dynamic components (such as the generator excitation system and the inverter control model). Based on the modified network equations, an iterative solution method is used to solve the node voltages and phase angles, while also checking the convergence of the network equations. The convergence condition is usually that the change in node voltage is less than a set threshold. If this is met, the simulation has converged for the current time step, and the system state is updated before entering the next time step. The simulation is repeated until the maximum simulation time is reached or the set termination condition is set.

[0082] The power system transient simulation method based on virtual admittance provided by the present invention is further introduced below through another embodiment.

[0083] See Figure 2 The power system transient simulation method based on virtual admittance provided in this embodiment includes the following simulation process:

[0084] Obtain the node voltage V and phase angle value of each dynamic element in the power system at the current moment , use the phase angle value to perform the following vector decomposition on the node voltage on the x-axis and y-axis to obtain the voltage components:

[0085]

[0086] in, and Represents the node voltage The x-axis and y-axis components of Indicates the phase angle value.

[0087] During the first iteration of each time step of the transient simulation, the virtual admittance of each dynamic element is calculated.

[0088] Firstly, the voltage component is calculated based on the linear sensitivity method. and Set the disturbance amount separately and , the voltage component and Input the dynamic model of the dynamic element to obtain the injected current and ; Apply a disturbance in the x-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the first node injection current component ; Apply a disturbance in the y-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the second node injection current component .

[0089] The following set of equations is constructed based on the calculated node voltages and node injection currents:

[0090]

[0091]

[0092] Solve the above equations to get the virtual admittance matrix of each dynamic element .

[0093] Among them, the virtual admittance matrix Is a 2×2 matrix. Assuming that the system has m dynamic elements, the virtual admittance matrix will be obtained , a small perturbation applied to the voltage and Should be less than 0.01.

[0094] The virtual admittance matrices of all dynamic elements in the power system are formed into diagonal block matrices, and the initial network equations are corrected using the diagonal block matrices according to the following relationship: Correction:

[0095]

[0096] Solve the above equations for , we get the new network equation, where represents the node admittance matrix of the power system, represents the node voltage vector, represents the node injection current vector, Representing the diagonal block matrix composed of the virtual admittance matrices of all dynamic elements, it has the following expression:

[0097]

[0098] Where n represents the number of dynamic elements in the power system, Represents the virtual admittance matrix of the nth dynamic element. For nodes in the system that have no dynamic elements connected, their virtual admittance is set to 0 matrix.

[0099] Use the network equation to perform transient simulation of the power system at the current time step until the simulation convergence conditions are met. The simulation convergence conditions for each time step are:

[0100]

[0101] Where k represents the number of iterations per time step, and represent the node voltages at the kth and k-1th iterations in the same time step, Indicates the convergence threshold.

[0102] The above embodiments provide a method for transient simulation of a power system based on virtual admittance, in which a corresponding virtual admittance matrix is calculated according to the node voltage and phase angle value of each dynamic element at the current moment, and the network equation of the system is corrected using the virtual admittance matrix, thereby improving the convergence of the transient simulation. The virtual admittance matrix is used to simulate the real response of the dynamic elements, so that the system model can be equivalently transformed even in the absence of an explicit mathematical model of the element. In particular, for systems with new energy grid connection, it is possible to achieve equivalent transformation of the simulation model of the entire system with the goal of improving convergence, thereby solving the problem of non-convergence of the simulation.

[0103] In order to verify the effectiveness of the simulation method proposed in this application, an improved IEEE-9 node system is used below for illustration. In this improved system, based on the standard IEEE-9 node system, node 5 is connected to a wind farm and node 6 is connected to a photovoltaic power station.

[0104] See Figure 3 , which illustrates an improved IEEE-9 node system. On this basis, a wind farm is connected to node 5 and a photovoltaic power station is connected to node 6. The dynamic model of the new energy station in the system adopts the encapsulated DLL model provided by the manufacturer. The line faults in the system are analyzed through the time domain simulation method proposed in this application to obtain the dynamic response of each node and each dynamic component in the entire system.

[0105] Figures 4-6The node voltage test results of the wind farm, photovoltaic power station and synchronous generator at node 1 are shown respectively. Figures 7 and 8 The simulation iteration results of the node voltage at the wind farm grid connection point and the photovoltaic power station grid connection point in the first time step after the system fault are shown respectively. It is clear from the simulation results that, using the simulation method proposed in this application, the algorithm can quickly converge to the final solution of the system model for each time step during the iterative calculation process. In contrast, when the method proposed in this application is not used, the difference between two consecutive iterative calculations in the algorithm solution process becomes increasingly larger, and the simulation results eventually diverge, making it impossible to continue the simulation.

[0106] The above-disclosed embodiments describe in detail a method for transient simulation of a power system based on virtual admittance. The above-disclosed method can be implemented using various forms of equipment. Therefore, the present invention also discloses a power system transient simulation device based on virtual admittance corresponding to the above-disclosed method. Specific embodiments are given below for detailed description.

[0107] like Figure 9 As shown, one embodiment of the present invention provides a power system transient simulation device based on virtual admittance, comprising:

[0108] The data acquisition module 902 is used to obtain the node voltage and phase angle value of each dynamic element in the power system to be simulated at the current moment;

[0109] A virtual admittance calculation module 904 is configured to calculate the node injection current of each dynamic element based on the node voltage and phase angle value of each dynamic element, and calculate the virtual admittance matrix of each dynamic element according to the node voltage and node injection current of each dynamic element;

[0110] A network equation correction module 906 is used to correct the network equation of the current time step using a virtual admittance matrix;

[0111] The transient simulation module 908 is used to perform transient simulation of the power system at the current time step using the network equations until the simulation convergence condition is met.

[0112] The device provided in the embodiment of the present application has the same implementation principle and technical effects as those in the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference can be made to the corresponding content in the aforementioned method embodiment.

[0113] The following embodiments illustrate this method using a computer device as an example. It is understood that the computer device may be any device with computing and processing capabilities, including, but not limited to, a server or a personal laptop. In one embodiment, the computer device may be an application server, which may be a server for running the application under test.

[0114] See Figure 10 , which shows a hardware block diagram of an electronic device, which is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital assistants, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present application described and / or claimed herein.

[0115] like Figure 10 As shown, the electronic device includes: at least one processor 1, at least one communication interface 2, at least one memory 3 and at least one communication bus 4;

[0116] In the embodiment of the present application, the number of the processor 1, the communication interface 2, the memory 3, and the communication bus 4 is at least one, and the processor 1, the communication interface 2, and the memory 3 communicate with each other through the communication bus 4;

[0117] The processor 1 may be a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention;

[0118] The memory 3 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory;

[0119] The memory stores a program, and the processor can call the program stored in the memory, wherein the program is used to implement various processing flows of the aforementioned power system transient simulation solution based on virtual admittance.

[0120] An embodiment of the present invention also provides a readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the computer program implements the various processing flows of the power system transient simulation scheme based on virtual admittance provided in the above embodiment and / or any possible implementation method in combination with the embodiment.

[0121] The methods and related devices mentioned in the above embodiments are described with reference to the method flow charts and / or structural diagrams provided in the embodiments of the present application. Specifically, each process and / or block in the method flow charts and / or structural diagrams, as well as the combination of processes and / or blocks in the flow charts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 Schematic diagram of one or more processes and / or structures Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including the instruction device, which implements the function specified in the process. Figure 1 Schematic diagram of one or more processes and / or structures Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 The flow or flows and / or structures illustrate the steps of the functions specified in one block or multiple blocks.

[0122] The above embodiments have described the invention in particular detail with respect to possible scenarios, and those skilled in the art will recognize that the invention can be practiced through other embodiments. The specific naming of components, capitalization of terms, attributes, data structures, or any other programming or structural aspects are not mandatory or important, and the mechanisms or features of the invention may have different names, forms, or procedures. The system may be implemented through a combination of hardware and software (as described), entirely through hardware elements, or entirely through software elements. The specific division of functions between the various system components described herein is exemplary only and not mandatory; rather, the functions performed by a single system component may be performed by multiple components, or the functions performed by multiple components may be performed by a single component.

[0123] Those skilled in the art will appreciate that the various steps of the method disclosed above can be implemented by a general-purpose computing device. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Alternatively, they can be implemented using program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module for implementation. Thus, the embodiments disclosed herein are not limited to any specific combination of hardware and software.

[0124] The programs executable by these computing devices (also referred to as programs, software, software applications, or code) include machine instructions for programmable processors and can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, apparatus, and / or device (e.g., a magnetic disk, an optical disk, a memory, a programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0125] Certain aspects of the present invention include the process steps and instructions described herein in the form of algorithms. It should be noted that the process steps and instructions of the present invention can be implemented in software, firmware and / or hardware, and when implemented in software, they can be downloaded, stored on different platforms used by various operating systems, and operated from the platforms.

[0126] Those skilled in the art will understand that the structures shown in the accompanying drawings are merely block diagrams of partial structures related to the scheme of the present application, and do not constitute a limitation on the terminal device to which the scheme of the present application is applied. The specific terminal device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0127] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "possible design" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0128] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0129] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for transient simulation of power system based on virtual admittance, characterized in that: include: Obtaining the node voltage and phase angle values of each dynamic element in the power system to be simulated at the current moment; The node voltage is vector-decomposed using the phase angle value to obtain voltage components. and ; The voltage component is analyzed based on the linear sensitivity method and Set the disturbance amount separately and ; The voltage component and Input the dynamic model of the dynamic element to obtain the injected current and ; Apply a disturbance in the x-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the first node injection current component ; Apply a disturbance in the y-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the second node injection current component ; The following set of equations is constructed using the voltage component, the first node injection current component, and the second node injection current component: ； ； Solve the equations to get the virtual admittance matrix of each dynamic element ; The network equation of the current time step is corrected using the virtual admittance matrix to obtain a new network equation, which specifically includes: Combining the virtual admittance matrices of all dynamic elements in the power system into a diagonal block matrix; Use the diagonal block matrix to calculate the initial network equation according to the following relationship Correction: ； Solve the relationship , we get the new network equation, where represents the network admittance matrix of the power system, represents the node voltage vector, represents the node injection current vector, Representing the diagonal block matrix composed of the virtual admittance matrices of all dynamic elements, it has the following expression: ； Where n represents the number of dynamic elements in the power system, represents the virtual admittance matrix of the nth dynamic element; The new network equation is used to perform transient simulation of the power system at the current time step until the simulation convergence condition is met.

2. The method according to claim 1, characterized in that The method of performing vector decomposition of the node voltage using the phase angle value to obtain the voltage components includes: The node voltage is vector-decomposed on the x-axis and y-axis using the phase angle value. The specific decomposition is as follows: ； in, and Represents the node voltage The x-axis and y-axis components of Indicates the phase angle value.

3. The method according to claim 1, characterized in that The simulation convergence conditions include: ； Where k represents the number of iterations per time step, and represent the node voltages at the kth and k-1th iterations in the same time step, Indicates the convergence threshold.

4. A power system transient simulation device based on virtual admittance, characterized in that: include: A data acquisition module is used to obtain the node voltage and phase angle value of each dynamic element in the power system to be simulated at the current moment; The virtual admittance calculation module is used to perform the virtual admittance matrix calculation process in the first iteration calculation of the current time step. The virtual admittance matrix calculation process includes: The voltage component is analyzed based on the linear sensitivity method and Set the disturbance amount separately and ; The voltage component and Input the dynamic model of the dynamic element to obtain the injected current and ; Apply a disturbance in the x-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the first node injection current component ; Apply a disturbance in the y-axis direction of the node voltage ,Bundle The dynamic model of the dynamic element is input as a variable to obtain the second node injection current component ; The following set of equations is constructed using the voltage component, the first node injection current component, and the second node injection current component: ； ； Solve the equations to get the virtual admittance matrix of each dynamic element ; The network equation correction module is used to correct the network equation of the current time step using the virtual admittance matrix, specifically including: Combining the virtual admittance matrices of all dynamic elements in the power system into a diagonal block matrix; Use the diagonal block matrix to calculate the initial network equation according to the following relationship Correction: ； Solve the relationship , we get the new network equation, where represents the network admittance matrix of the power system, represents the node voltage vector, represents the node injection current vector, Representing the diagonal block matrix composed of the virtual admittance matrices of all dynamic elements, it has the following expression: ； Where n represents the number of dynamic elements in the power system, represents the virtual admittance matrix of the nth dynamic element; The transient simulation module is used to perform transient simulation of the power system at the current time step using the network equations until the simulation convergence conditions are met.

5. An electronic device, characterized in that: The device comprises a memory storing computer executable instructions and a processor, and when the computer executable instructions are executed by the processor, the device executes the power system transient simulation method based on virtual admittance as described in any one of claims 1 to 3.

6. A readable storage medium, characterized in that: A computer executable program is stored, and when the program is executed, the power system transient simulation method based on virtual admittance as described in any one of claims 1 to 3 can be implemented.

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