Power electronic transformer modeling and simulation method, equipment, medium and product
By disaggregating the topological structure of the power electronic transformer and establishing a down-order equivalent model, the problem of difficulty in taking into account the accuracy and efficiency of the electromagnetic transient simulation of the power electronic transformer in the new power system is solved, and efficient simulation calculation is achieved.
Patent Information
- Application Number
- CN202411528085.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-03-28
AI Technical Summary
In the new power system, the electromagnetic transient simulation of power electronic transformers is difficult to take into account both accuracy and computational efficiency, especially when the time constants of large-scale power grids and AC and DC equipment are large.
The topological structure of the multi-active bridge power electronic transformer is discretized by the implicit trapezoidal integration method, and the original node voltage equation is obtained, and the order reduction is reduced by the transform element elimination method, and the order reduction is equal value model of the multi-active bridge type is established, and electromagnetic transient simulation is performed.
The calculation amount of the simulation solution process is significantly reduced through the down-order equivalent model, the calculation speed is improved, and the original simulation accuracy is maintained under a large step size, meeting the electromagnetic transient simulation needs of large-scale new power systems.
Smart Images
Figure CN119720479A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of power electronic transformers, and in particular to a power electronic transformer modeling and simulation method, equipment, medium and product. Background Art
[0002] The power system is transforming into a new power system, and the electromagnetic transient characteristics of the system are becoming increasingly complex. Through accurate modeling of relevant components of the power system and detailed and fast electromagnetic transient simulation analysis, the dynamic characteristics of the power system can be accurately grasped, providing important help for the planning, design, construction, development and operation practice of the power system. In order to reveal the operating laws and dynamic characteristics of the new power system and develop equipment and devices suitable for the new power system, fast and accurate electromagnetic transient simulation has become an important technical means.
[0003] As the scale of AC and DC power grids continues to expand, the requirements for the speed and accuracy of electromagnetic transient simulation continue to increase. The electromagnetic transient simulation of new power systems faces the following challenges:
[0004] 1) High degree of power electronics. The proportion of renewable energy generation in the total power supply in new power systems is increasing, such as photovoltaic and wind power generation. In order to improve the power quality of such renewable energy generation connected to the grid, a large number of power electronic devices need to be introduced. In addition, the large increase in high-voltage direct current transmission and flexible direct current transmission projects has significantly increased the number and distribution range of power electronic transformers (PET) in the power grid. This type of equipment is composed of many high-frequency switching devices, which frequently operate in a very short time, resulting in frequent changes in the topology of the corresponding equipment, thereby restricting the simulation speed of the entire system on the electromagnetic transient time scale. Foreign simulation platforms do not have mature modeling methods or efficient simulation models for power electronic transformers, but many models either sacrifice simulation speed to a large extent in pursuit of accuracy, or reduce accuracy in order to speed up simulation, and there is no good general modeling method that can unify power electronic transformers of various topologies. Therefore, traditional simulation tools cannot well meet the requirements of new power systems for simulation accuracy and speed.
[0005] 2) The time constants of AC and DC devices vary greatly. Because there are a large number of power electronic devices in the new power system, there will be a large number of high-frequency switching of switching devices, and the transient process is rapid. In order to accurately reflect the switching time, a small step size is usually used for simulation. The transient response of the AC power grid is relatively slow. In order to speed up the simulation speed, a large step size simulation is often used. This leads to a large difference in the simulation step size on the AC and DC sides. In order to ensure the simulation accuracy, the entire system is simulated with a small step size, which will greatly reduce the simulation speed and cannot meet the simulation requirements of large-scale AC and DC power grids.
[0006] 3) The order of system equations is high. With the construction of new power systems, the grid structure is becoming increasingly complex, and the emergence of large-scale AC / DC power grids has led to prominent AC / DC hybrid characteristics. However, traditional electromagnetic transient simulation technologies (state variable analysis method and node analysis method) require solving differential equations. Due to the use of a large number of power electronic equipment, the scale of new power systems will become very large, and the order of differential equations generated during the system solution process will increase sharply, resulting in a sharp increase in the amount of calculation for simulation solutions.
[0007] Electromagnetic transient simulation must be both accurate and fast. However, the changes in the above three aspects have made the contradiction between the accuracy and speed of power electronic transformer simulation more prominent. The existing methods are no longer applicable and it is urgent to improve or propose new methods.
[0008] The existing electromagnetic transient simulation models for power electronic transformers all strive to achieve a compromise between the accuracy of the detailed model and the simulation efficiency.
[0009] The existing power electronic transformer models can be roughly divided into three categories:
[0010] (1) Detailed model
[0011] All control systems and capacitor voltage calculation records of power electronic transformers are retained, which can be used to analyze abnormal problems inside PET, such as harmonic analysis. However, since the detailed model retains the complete topological structure of PET, the calculation amount is large and it is not suitable for the analysis of large systems. It is often used as a reference model for testing other improved models. Since the detailed model takes into account the transient behavior of semiconductor switches, a large number of electrical nodes need to be solved, and an algorithm for quickly solving nonlinear switching events is also required. The calculation method is required to have the ability to solve "rigid" differential equations. The overall calculation time is still very long. It is mainly used to verify other simplified equivalent models and is not suitable for simulation modeling of large-scale power systems.
[0012] (2) Mean value model
[0013] The average value model is based on the power equation and the half-cycle current waveform. It no longer models the switching devices, reactors, and transformers in detail. Instead, it replaces the PET submodule with a controllable average current source. By taking the average value of the PET current in one cycle, a reduced-order average model with an RLC circuit and a controllable source is obtained. Compared with the detailed model, the average value model simplifies the PET to a certain extent to achieve faster simulation calculations. The disadvantage of the average value model is that the average value equivalence of the system will ignore the dynamic characteristics of each submodule inside the PET, which greatly reduces the accuracy of the system in steady state, resulting in a large truncation error and inability to effectively simulate fault conditions.
[0014] (3) Constant admittance model
[0015] The constant admittance model uses a small inductor equivalent to the on state and a small capacitor equivalent to the off state, and ensures that GL=GC. It has the characteristic that the node admittance matrix does not change with the switch state, and there is no need to recalculate the node admittance matrix after a step operation. With this characteristic, the constant admittance model can effectively solve the matrix time-varying problem caused by switch switching and improve the simulation rate. However, since the off current and on voltage of the device cannot be immediately reduced to 0 after the switch action, the constant admittance model will generate a large virtual power loss during this period. This virtual power loss will increase with the increase of the simulation step size and the number of switch switching, seriously affecting the simulation accuracy of the model. Therefore, the simulation step size of the constant admittance model is limited to the sub-microsecond level, which is not conducive to improving the simulation efficiency and scale.
[0016] In summary, the shortcomings of the existing technology are mainly: in the context of large-scale power grids, there is a contradiction between accuracy and computational efficiency in electromagnetic transient simulation of power electronic transformers. Therefore, in order to meet the needs of electromagnetic transient simulation of large-scale new power systems, it is urgent to provide a new modeling and simulation method for power electronic transformers. Summary of the invention
[0017] The purpose of this application is to provide a power electronic transformer modeling and simulation method, equipment, medium and product that can meet the needs of electromagnetic transient simulation of large-scale new power systems.
[0018] To achieve the above objectives, this application provides the following solutions:
[0019] In a first aspect, the present application provides a power electronic transformer modeling and simulation method, the power electronic transformer modeling and simulation method comprising:
[0020] Obtain the topology of a multi-active bridge power electronic transformer;
[0021] The topological structure is discretized using the implicit trapezoidal integration method to obtain the original node voltage equation;
[0022] The original node voltage equation is reduced to obtain a reduced-order node voltage equation;
[0023] A reduced-order equivalent model of multi-active bridge type is established based on the reduced-order node voltage equation;
[0024] Electromagnetic transient simulation is performed based on the reduced-order equivalent model of multiple active bridge types.
[0025] Optionally, the topological structure is discretized using an implicit trapezoidal integration method to obtain an original node voltage equation, specifically including:
[0026] The topological structure is discretized by using the implicit trapezoidal integration method. The topological structure after discretization is that the dynamic elements in the topological structure are converted into constant admittance and variable historical current sources, and the switch group is equivalent to a binary resistor.
[0027] Determine the system node admittance matrix and the equivalent injection current source of each node according to the topological structure after discretization;
[0028] The original node voltage equation is determined based on the system node admittance matrix and the equivalent injection current source of each node.
[0029] Optionally, the original node voltage equation is:
[0030]
[0031] Among them, i hE 、i hI u is the column vector of the historical current source injected into the external nodes and internal nodes; E 、u I is the voltage column vector of the external nodes and internal nodes, Y E is the external node self-admittance, Y IE and Y EI is the mutual admittance of internal and external nodes, Y I is the internal node self-admittance.
[0032] Optionally, the method of reducing the order is transformation elimination.
[0033] Alternatively, the reduced-order node voltage equation is:
[0034] i hEN =Y EN u E ;
[0035] Among them, i hEN is the node current, Y EN is the reduced-order node admittance matrix.
[0036] Optionally, electromagnetic transient simulation is performed according to a reduced-order equivalent model of a multi-active bridge type, specifically including:
[0037] Perform initialization processing;
[0038] The switch action is judged based on the binary resistance;
[0039] According to the judgment result, the original node admittance matrix in the original node voltage equation and the values of the corresponding elements in the historical current source are updated;
[0040] According to the updated original node voltage equation, the values of corresponding elements in the reduced-order node admittance matrix and the node current are updated;
[0041] updating the reduced-order equivalent model according to the updated reduced-order node voltage equation;
[0042] The reduced-order equivalent model is solved to obtain the voltage of the external node of the power electronic transformer;
[0043] Determine the voltage of the internal node; and update the historical current source according to the voltage of the internal node and the voltage of the external node;
[0044] If the simulation is not finished, the process returns to the step of judging the switch action according to the binary resistance until the simulation is finished.
[0045] In a second aspect, the present application provides a power electronic transformer modeling and simulation device, the power electronic transformer modeling and simulation device comprising:
[0046] A topology acquisition module, used to acquire the topology of a multi-active bridge type power electronic transformer;
[0047] The original node voltage equation determination module is used to discretize the topological structure using an implicit trapezoidal integration method to obtain the original node voltage equation;
[0048] A reduced-order node voltage equation determination module is used to reduce the order of the original node voltage equation to obtain a reduced-order node voltage equation;
[0049] A reduced-order equivalent model building module is used to build a reduced-order equivalent model of multiple active bridge types according to reduced-order node voltage equations;
[0050] Simulation module for electromagnetic transient simulation based on reduced-order equivalent models of multiple active bridge types.
[0051] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the power electronic transformer modeling and simulation method.
[0052] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power electronic transformer modeling and simulation method.
[0053] In a fifth aspect, the present application provides a computer program product, including a computer program, which implements the power electronic transformer modeling and simulation method when executed by a processor.
[0054] According to the specific embodiments provided in this application, this application has the following technical effects:
[0055] The present application provides a power electronic transformer modeling and simulation method, equipment, medium and product. By discretizing the topological structure of the original multiple active bridge (MAB) type power electronic transformer, an equivalent circuit and node voltage equation corresponding to the original topological structure are obtained. The method is not only applicable to MAB type power electronic transformers, but also applicable to power electronic transformers of any topological form such as DAB type, CHB-DAB type, SAB type, etc. Since the method starts from the basic equation of the power electronic transformer, the equivalent circuit obtained is both concise in form and universal. When the number of external ports in the power electronic transformer changes, only the corresponding nodes need to be added or deleted in the equivalent model, and only the dimensions need to be changed in the node admittance matrix and the historical current source, and the corresponding variables need to be accumulated at the corresponding positions, which has good scalability. The equivalent process only involves the mathematical transformation of the node admittance matrix and the historical current source vector, which can maintain a high simulation accuracy; by reducing the order of the device node voltage equation, the calculation amount of the MAB electromagnetic transient simulation solution process is greatly reduced, and the calculation speed can be significantly improved. The equivalent method is not limited by the simulation step size, and the original performance remains unchanged at a larger step size. BRIEF DESCRIPTION OF THE DRAWINGS
[0056] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0057] Figure 1 This is a schematic diagram of a flow chart of a power electronic transformer modeling and simulation method in one embodiment of the present application;
[0058] Figure 2 It is a schematic diagram of the topological structure of the MAB type power electronic transformer;
[0059] Figure 3It is a schematic diagram of the simulation process of MAB type power electronic transformer;
[0060] Figure 4 It is a schematic diagram of the reduced-order equivalent model structure. DETAILED DESCRIPTION
[0061] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0062] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0063] In an exemplary embodiment, Figure 1 As shown, a power electronic transformer modeling and simulation method is provided, the method comprising the following S101 to S105. Wherein:
[0064] S101, obtaining a topological structure of a multi-active bridge type power electronic transformer;
[0065] like Figure 2 As shown in the figure, the topology of the MAB type PET is a multi-port device. Taking the existing three-input and one-output topology as an example, there are three ports on the input side and one port on the output side. Each port is equipped with a parallel capacitor to weaken the DC voltage ripple. The AC-DC conversion of each MAB port is completed by the corresponding full-bridge submodule / H-bridge. The switch group consists of an IGBT and a power diode in anti-parallel connection. The AC side is realized by a single-phase four-winding transformer to achieve power conversion.
[0066] S102, using an implicit trapezoidal integration method to discretize the topological structure and obtain an original node voltage equation;
[0067] S102 specifically includes:
[0068] The topological structure is discretized by using the implicit trapezoidal integration method. The topological structure after discretization is that the dynamic elements in the topological structure are converted into constant admittance and variable historical current sources, and the switch group is equivalent to a binary resistor.
[0069] Determine the system node admittance matrix and the equivalent injection current source of each node according to the topological structure after discretization;
[0070] The original node voltage equation is determined based on the system node admittance matrix and the equivalent injection current source of each node.
[0071] Discretization processing obtains the system node admittance matrix Y of MAB and the equivalent injection current source i of each node h , forming the 16th-order original node voltage equation of MAB h =Yu, that is, the original node voltage equation is:
[0072]
[0073] Among them, i hE 、i hI u is the column vector of the historical current source injected into the external nodes and internal nodes; E 、u I is the voltage column vector of the external nodes and internal nodes, Y E is the external node self-admittance, Y IE and Y EI is the mutual admittance of internal and external nodes, Y I is the internal node self-admittance.
[0074] S103, reducing the order of the original node voltage equation to obtain a reduced-order node voltage equation; the method of reducing the order is transformation elimination.
[0075] The specific reduction process is:
[0076] Expand formula (1) into two sets of equations:
[0077] i hE =Y E u E +Y EI u I (2)
[0078] i hI =Y IE u E +Y I u I (3)
[0079] According to formula (3), the voltage u of the internal node is I The expression is:
[0080]
[0081] According to formula (2) and formula (4), the voltage of the internal node is eliminated, and we get:
[0082] i hEN =Y EN u E (5)
[0083] Among them, i hEN is the node current, Y ENis the reduced-order node admittance matrix.
[0084] According to formula (5), the original node voltage equation is transformed and eliminated to eliminate the elements or variables related to the internal nodes, thus forming a reduced-order node voltage equation containing only the external nodes.
[0085] S104, establishing a reduced-order equivalent model of a multi-active bridge type according to a reduced-order node voltage equation;
[0086] like Figure 4 As shown in FIG. 1 , the equivalent network N of the reduced-order equivalent model only includes the mutual admittance branches between the external nodes and the node injection current source, and there are no other internal nodes. The equivalent model is reduced from the 16th order of the original equation to the 8th order, and the size of the admittance matrix is reduced to 1 / 4 of the original.
[0087] S105, performing electromagnetic transient simulation according to the reduced-order equivalent model of the multi-active bridge type.
[0088] After processing the switch action and updating the node admittance matrix Y in each simulation time step, a new reduced-order node voltage equation is generated. EN and node current i hEN Add to the admittance matrix of the entire system and the node current to perform electromagnetic transient calculations, that is, invert the node admittance matrix, from u = Y -1 i calculates the node voltage, and the node voltage obtained at this time is the external node voltage u of the equivalent model E , the voltage u of the internal node eliminated in the equalization process needs to be calculated by formula (4) I , and thus the node voltage u of the MAB is obtained, and the branch currents and historical current sources of the entire device are inversely solved and updated for the next simulation calculation. Through the above calculation process, the reduced-order solution of the MAB type PET can be achieved.
[0089] The specific process is as follows Figure 3 As shown:
[0090] S1, perform initialization processing;
[0091] S2, judging the switch action based on the binary resistance;
[0092] S3, updating the original node admittance matrix in the original node voltage equation and the values of corresponding elements in the historical current source according to the judgment result;
[0093] S4, updating the values of corresponding elements in the reduced-order node admittance matrix and the node current according to the updated original node voltage equation;
[0094] S5, updating the reduced-order equivalent model according to the updated reduced-order node voltage equation;
[0095] S6, solving the reduced-order equivalent model to obtain the voltage of the external node of the power electronic transformer;
[0096] S7, determining the voltage of the internal node; and updating the historical current source according to the voltage of the internal node and the voltage of the external node;
[0097] S8, if the simulation is not finished, return to the step of judging the switch action according to the binary resistance until the simulation is finished.
[0098] The basic principle of electromagnetic transient simulation calculation is to solve the node voltage equation Yu=i and calculate the voltage of each node of the system. This process requires the inverse calculation of the system node admittance matrix Y. Therefore, the scale of the simulation calculation is cubically related to the order of Y. This application transforms the power electronic transformer with a complex topology into a 4-port network with only 8 nodes by reducing the order equivalence, which can greatly reduce the amount of simulation calculation, effectively solve the problem of difficulty in balancing the accuracy and efficiency of electromagnetic transient simulation of systems connected to a large number of power electronic transformers, and improve the simulation calculation speed without sacrificing simulation accuracy.
[0099] The present application performs an equivalent reduction on the original MAB topology, and forms an equivalent model containing only 8 external nodes from the original detailed model with 16 nodes. The same equivalent model can be established for MABs of any topology. When the number of MAB ports increases, such as changing from three inputs and one output to X input and Y output, or cascading a full-bridge submodule at the input port, the equivalent method proposed in the present invention can also be applied for order reduction. Based on the discretized detailed model circuit, the corresponding original node voltage equation is obtained according to the different working modes of the switching device, and the nodes inside the device are eliminated by Gaussian elimination to obtain the reduced-order node voltage equation, which is then used to participate in the electromagnetic transient calculation of the system.
[0100] After the forward solution is completed by reducing the node voltage equation, the voltage of the external node is obtained instead of all nodes. To realize the inverse solution calculation of the branch current, it is necessary to first obtain the voltage of some nodes eliminated in the equivalent process. According to the relationship between the internal node voltage and the corresponding injection current and the external node voltage, the voltage of all nodes in the system can be obtained, and then the branch current can be inversely solved and the historical current source can be updated.
[0101] According to the topological structure of the MAB type power electronic transformer, the equivalent circuit and node voltage equation corresponding to the original topological structure are obtained by discretization. It is not only applicable to the MAB type power electronic transformer, but also to power electronic transformers of any topological form such as DAB type, CHB-DAB type, SAB type, etc. Since it starts from the basic equation of the power electronic transformer, the equivalent circuit obtained is both concise and universal. When the number of external ports in the power electronic transformer changes, only the corresponding nodes need to be added or deleted in the equivalent model, and the system node admittance matrix Y and the historical current source i h You only need to change the dimension and accumulate the corresponding variables at the corresponding positions, which has good scalability.
[0102] The equivalent method proposed in this application does not involve any simplification process in the equivalent transformation process of the discretized model of the MAB type power electronic transformer. The equivalent process only involves the mathematical transformation of the node admittance matrix and the historical current vector, so a high simulation accuracy can be maintained.
[0103] The solution of electromagnetic transient simulation is actually to calculate the voltage of each node through the system node voltage equation. Since the node admittance matrix needs to be inverted during the calculation process, the simulation calculation amount will change according to the cubic relationship as the order increases or decreases. The present invention greatly reduces the amount of calculation in the MAB electromagnetic transient simulation solution process by reducing the order of the device node voltage equation, which can significantly improve the calculation speed. The equivalent method is not limited by the simulation step size and still maintains the original performance at a larger step size. Although this equivalent method has certain matrix transformation calculations in the modeling process, as the number of device nodes increases, the full process calculation speed of the reduced-order equivalent model is significantly higher than directly solving the original node voltage equation of the device.
[0104] Based on the same inventive concept, the embodiment of the present application also provides a power electronic transformer modeling and simulation device for implementing the power electronic transformer modeling and simulation method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more power electronic transformer modeling and simulation device embodiments provided below can refer to the limitations of the power electronic transformer modeling and simulation method above, and will not be repeated here.
[0105] In an exemplary embodiment, a power electronic transformer modeling and simulation device is provided, comprising:
[0106] A topology acquisition module, used to acquire the topology of a multi-active bridge type power electronic transformer;
[0107] The original node voltage equation determination module is used to discretize the topological structure using an implicit trapezoidal integration method to obtain the original node voltage equation;
[0108] A reduced-order node voltage equation determination module is used to reduce the order of the original node voltage equation to obtain a reduced-order node voltage equation;
[0109] A reduced-order equivalent model building module is used to build a reduced-order equivalent model of multiple active bridge types according to reduced-order node voltage equations;
[0110] Simulation module for electromagnetic transient simulation based on reduced-order equivalent models of multiple active bridge types.
[0111] In an exemplary embodiment, a computer device is provided, which may be a server or a terminal. The computer device includes a processor, a memory, an input / output interface (I / O for short) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a power electronic transformer modeling and simulation method is implemented.
[0112] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.
[0113] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.
[0114] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.
[0115] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).
[0116] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.
[0117] In this application, all actions to obtain signals, information or data are carried out in compliance with the relevant data protection laws and policies of the country where they are located and with the authorization given by the owner of the corresponding device.
[0118] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0119] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.
Claims
1. A power electronic transformer modeling and simulation method, characterized in that: The power electronic transformer modeling and simulation method comprises: Obtain the topology of a multi-active bridge power electronic transformer; The topological structure is discretized using the implicit trapezoidal integration method to obtain the original node voltage equation; The original node voltage equation is reduced to obtain a reduced-order node voltage equation; A reduced-order equivalent model of multi-active bridge type is established based on the reduced-order node voltage equation; Electromagnetic transient simulation is performed based on the reduced-order equivalent model of multiple active bridge types.
2. The power electronic transformer modeling and simulation method according to claim 1, characterized in that: The topological structure is discretized by using the implicit trapezoidal integration method to obtain the original node voltage equation, which specifically includes: The topological structure is discretized by using the implicit trapezoidal integration method. The topological structure after discretization is that the dynamic elements in the topological structure are converted into constant admittance and variable historical current sources, and the switch group is equivalent to a binary resistor. Determine the system node admittance matrix and the equivalent injection current source of each node according to the topological structure after discretization; The original node voltage equation is determined based on the system node admittance matrix and the equivalent injection current source of each node.
3. The power electronic transformer modeling and simulation method according to claim 1 or claim 2, characterized in that: The original node voltage equation is: Among them, i hE 、i hI u is the column vector of the historical current source injected into the external nodes and internal nodes; E 、u I is the voltage column vector of the external nodes and internal nodes, Y E is the external node self-admittance, Y IE and Y EI is the mutual admittance of internal and external nodes, Y I is the internal node self-admittance.
4. The power electronic transformer modeling and simulation method according to claim 1, characterized in that: The method of reducing the order is transformation and elimination.
5. The power electronic transformer modeling and simulation method according to claim 3, characterized in that: The reduced-order node voltage equation is: i hEN =Y EN u E ; Among them, i hEN is the node current, Y EN is the reduced-order node admittance matrix.
6. The power electronic transformer modeling and simulation method according to claim 1, characterized in that: Electromagnetic transient simulation is performed based on the reduced-order equivalent model of multiple active bridge types, including: Perform initialization processing; The switch action is judged based on the binary resistance; According to the judgment result, the original node admittance matrix in the original node voltage equation and the values of the corresponding elements in the historical current source are updated; According to the updated original node voltage equation, the values of corresponding elements in the reduced-order node admittance matrix and the node current are updated; updating the reduced-order equivalent model according to the updated reduced-order node voltage equation; The reduced-order equivalent model is solved to obtain the voltage of the external node of the power electronic transformer; Determine the voltage of the internal node; and update the historical current source according to the voltage of the internal node and the voltage of the external node; If the simulation is not finished, the process returns to the step of judging the switch action according to the binary resistance until the simulation is finished.
7. A power electronic transformer modeling and simulation device, characterized in that: The power electronic transformer modeling and simulation device comprises: A topology acquisition module, used to acquire the topology of a multi-active bridge type power electronic transformer; The original node voltage equation determination module is used to discretize the topological structure using an implicit trapezoidal integration method to obtain the original node voltage equation; A reduced-order node voltage equation determination module is used to reduce the order of the original node voltage equation to obtain a reduced-order node voltage equation; A reduced-order equivalent model building module is used to build a reduced-order equivalent model of multiple active bridge types according to reduced-order node voltage equations; Simulation module for electromagnetic transient simulation based on reduced-order equivalent models of multiple active bridge types.
8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the power electronic transformer modeling and simulation method according to any one of claims 1 to 6.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the power electronic transformer modeling and simulation method described in any one of claims 1 to 6 is implemented.
10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the power electronic transformer modeling and simulation method described in any one of claims 1 to 6 is implemented.