Electromagnetic transient simulation modeling method and device for power electronic converter
By establishing a differential equation group of the power electronic converter and introducing stability factors and precision factors for discretization, the problem of balancing simulation accuracy and stability in electromagnetic transient simulation of power electronic converters is solved, and a more efficient simulation effect is achieved.
Patent Information
- Application Number
- CN202510943902.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-09-26
Smart Images
Figure CN120706118A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electromagnetic transient simulation modeling, and in particular to a method and device for electromagnetic transient simulation modeling of a power electronic converter. Background Art
[0002] The electromagnetic transient simulation modeling of power electronic converters requires writing the converter's Kirchhoff current equation and Kirchhoff voltage equation based on the converter's operating characteristics and basic circuit principles. These equations describing the operating principles and characteristics of power electronic converters contain calculus steps, and the equations need to be discretized to obtain discrete expressions. , where n is an integer representing the current simulation step size, represents the branch current of the current simulation step, represents the equivalent admittance matrix, represents the node voltage of the current simulation step, The equivalent historical current source representing the current simulation step can be correctly executed by the computer and complete the simulation calculation process. In the discretization process of the above equations, there are mainly three methods: forward Euler method, backward Euler method and trapezoidal integration method. Their mathematical meanings are as follows: Figure 1 shown. Figure 1 Figure (a) shows the forward Euler method, which is simple and easy to implement, but suffers from moderate accuracy and relatively poor convergence. Figure (b) shows the backward Euler method, which is characterized by good convergence and strong numerical stability. Figure (c) shows the trapezoidal integration method, which combines the advantages of the above two methods and has high discretization accuracy. It is a discretization method widely used in electromagnetic transient simulation modeling.
[0003] However, because new energy power electronic converters differ from other power system components in their diverse topologies, complex mechanisms, and pronounced nonlinear, strongly coupled characteristics, any of the aforementioned methods can lead to a struggle between accuracy and stability during electromagnetic transient simulation modeling. This manifests itself in the numerical stability of the trapezoidal integration rule, which leads to divergence of node voltages during the simulation. While the back-off and back-pull method can avoid numerical oscillations, it also reduces simulation accuracy to a certain extent. Therefore, effectively balancing stability and accuracy in electromagnetic transient simulation modeling for power electronic converters is a pressing technical challenge for those skilled in the art. Summary of the Invention
[0004] The present invention provides a method and device for electromagnetic transient simulation modeling of a power electronic converter, which is used to solve the technical problem that the existing electromagnetic transient simulation modeling of a power electronic converter is difficult to balance the stability and accuracy of the electromagnetic transient simulation modeling of the power electronic converter.
[0005] In view of this, a first aspect of the present invention provides a method for electromagnetic transient simulation modeling of a power electronic converter, comprising:
[0006] Establish the differential equations of the power electronic converter. The differential equations of the power electronic converter are: , where X is the state variable matrix, is the differential of X, U is the matrix of other variables except the state variables, A, B, and C are the first coefficient matrix, the second coefficient matrix, and the third coefficient matrix respectively. The state variables include: the branch current where the AC measuring inductor of the power electronic converter is located and the voltage of the node connected to the DC side capacitor of the power electronic converter;
[0007] Configure the stability factor and precision factor for the differential equations of the power electronic converter, discretize the differential equations of the power electronic converter, and obtain the discretized equations: ,in, is discrete time, is the state variable at the current moment, is the state variable at the previous moment, are other variables at the current moment, are other variables at the previous moment, 、 、 、 are the first discretization coefficient matrix, the second discretization coefficient matrix, the third discretization coefficient matrix and the fourth discretization coefficient matrix obtained by discretization respectively, is the stabilizing factor, is the precision factor;
[0008] Arrange the discretized equations to obtain the target equations: ,in, is the current of all branches connected to the power electronic converter. is the voltage of all nodes connected to the outside of the power electronic converter, is the equivalent admittance matrix of the power electronic converter, is the historical current source of the power electronic converter;
[0009] Based on the target equation group, the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter are solved, and the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter are sent to the electromagnetic transient solver, so that the electromagnetic transient solver completes the electromagnetic transient simulation modeling of the power electronic converter.
[0010] Optionally, the first discretization coefficient matrix is:
[0011]
[0012] The second discretization coefficient matrix is:
[0013]
[0014] The third discretization coefficient matrix is:
[0015]
[0016] The fourth discretization coefficient matrix is:
[0017] .
[0018] Optionally, the stability factor and precision factor meet the pre-conditions, which are: .
[0019] Optionally, the stability factor ranges from 0 to 1, and the precision factor ranges from 0 to 1.
[0020] A second aspect of the present invention provides a device for electromagnetic transient simulation modeling of a power electronic converter, comprising:
[0021] The differential equation building block is used to build the differential equations of the power electronic converter. The differential equations of the power electronic converter are , where X is the state variable matrix, is the differential of X, U is the matrix of other variables except the state variables, A, B, and C are the first coefficient matrix, the second coefficient matrix, and the third coefficient matrix respectively. The state variables include: the branch current where the AC measuring inductor of the power electronic converter is located and the voltage of the node connected to the DC side capacitor of the power electronic converter;
[0022] The discretization module is used to configure the stability factor and precision factor for the differential equation group of the power electronic converter, discretize the differential equation group of the power electronic converter, and obtain the discretized equation group: ,in, is discrete time, is the state variable at the current moment, is the state variable at the previous moment, are other variables at the current moment, are other variables at the previous moment, 、 、 、 are the first discretization coefficient matrix, the second discretization coefficient matrix, the third discretization coefficient matrix and the fourth discretization coefficient matrix obtained by discretization respectively, is the stabilizing factor, is the precision factor;
[0023] The adjustment module is used to sort out the discretized equations to obtain the target equations: ,in, is the current of all branches connected to the power electronic converter. is the voltage of all nodes connected to the outside of the power electronic converter, is the equivalent admittance matrix of the power electronic converter, is the historical current source of the power electronic converter;
[0024] The solving module is used to solve the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter based on the target equation group, and send the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter to the electromagnetic transient solver, so that the electromagnetic transient solver completes the electromagnetic transient simulation modeling of the power electronic converter.
[0025] Optionally, the first discretization coefficient matrix is:
[0026]
[0027] The second discretization coefficient matrix is:
[0028]
[0029] The third discretization coefficient matrix is:
[0030]
[0031] The fourth discretization coefficient matrix is:
[0032] .
[0033] Optionally, the stability factor and precision factor meet the pre-conditions, which are: .
[0034] Optionally, the stability factor ranges from 0 to 1, and the precision factor ranges from 0 to 1.
[0035] A third aspect of the present invention provides a fault ride-through device for a photovoltaic power generation system through a flexible direct current transmission system, the device comprising a processor and a memory:
[0036] The memory is used to store program code and transmit the program code to the processor;
[0037] The processor is used to execute the electromagnetic transient simulation modeling method of the power electronic converter according to any one of the first aspects according to the instructions in the program code.
[0038] A fourth aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program code, and the program code is used to execute the electromagnetic transient simulation modeling method of the power electronic converter described in any one of the first aspects.
[0039] From the above technical solutions, it can be seen that the electromagnetic transient simulation modeling method for power electronic converters provided by the present invention has the following advantages:
[0040] The electromagnetic transient simulation modeling method for a power electronic converter provided by the present invention establishes a differential equation system for the power electronic converter, introduces a stability factor and a precision factor to discretize the differential equation system for the power electronic converter, and then solves the target equation system obtained by discretization. The electromagnetic transient simulation modeling of the power electronic converter is completed by an electromagnetic transient solver. During the electromagnetic transient simulation modeling process of the power electronic converter, the stability factor and precision factor in the discretization of the converter modeling can be flexibly set according to different application scenarios and simulation requirements, effectively balancing the stability and precision of the simulation, thereby solving the technical problem that the existing electromagnetic transient simulation modeling of the power electronic converter is difficult to balance the stability and precision of the electromagnetic transient simulation modeling of the power electronic converter. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] 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 only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.
[0042] Figure 1 Schematic diagram of the mathematical meaning of the forward Euler method, backward Euler method and trapezoidal integration method;
[0043] Figure 2 A schematic flow chart of a method for electromagnetic transient simulation modeling of a power electronic converter provided in an embodiment of the present invention;
[0044] Figure 3 Schematic diagram comparing the simulation effect of the electromagnetic transient simulation modeling method for a power electronic converter provided in an embodiment of the present invention with the simulation effect of the existing trapezoidal integration method;
[0045] Figure 4 A schematic structural diagram of an electromagnetic transient simulation modeling device for a power electronic converter provided in an embodiment of the present invention;
[0046] Figure 5 The present invention provides a schematic structural diagram of an electromagnetic transient simulation modeling device for a power electronic converter. DETAILED DESCRIPTION
[0047] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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 making creative efforts shall fall within the scope of protection of the present invention.
[0048] For easier understanding, see Figure 2 The present invention provides an embodiment of a method for electromagnetic transient simulation modeling of a power electronic converter, comprising:
[0049] Step S1: Establish a differential equation group of the power electronic converter.
[0050] It should be noted that, combining the basic working principle of the power electronic converter with Kirchhoff's voltage law and Kirchhoff's current law, the differential equations of the power electronic converter are established: , where X is the state variable matrix, is the differential of X, U is the matrix of other variables except state variables, A, B, and C are the first coefficient matrix, the second coefficient matrix, and the third coefficient matrix respectively. The state variables include: the branch current where the AC measuring inductor of the power electronic converter is located and the voltage of the node connected to the DC side capacitor of the power electronic converter.
[0051] Step S2: configuring a stability factor and a precision factor for the differential equation group of the power electronic converter, and discretizing the differential equation group of the power electronic converter to obtain a discretized equation group.
[0052] It should be noted that the configuration stability factor and precision factor Two parameters, differential equations for power electronic converters Perform discretization and obtain the discretized equations: ,in, is discrete time, is the state variable at the current moment, is the state variable at the previous moment, are other variables at the current moment, are other variables at the previous moment, 、 、 、 They are the first discretization coefficient matrix, the second discretization coefficient matrix, the third discretization coefficient matrix and the fourth discretization coefficient matrix obtained by discretization respectively.
[0053] Differential equations for power electronic converters When performing discretization, the stability factors and precision factors of different state variables are independent of each other.
[0054] In one embodiment, the first discretization coefficient matrix is:
[0055]
[0056] The second discretization coefficient matrix is:
[0057]
[0058] The third discretization coefficient matrix is:
[0059]
[0060] The fourth discretization coefficient matrix is:
[0061] .
[0062] In one embodiment, the stability factor and the precision factor meet the preset conditions, which are: The stability factor ranges from 0 to 1, and the precision factor ranges from 0 to 1. They can be flexibly selected according to different power electronic converter topologies and different simulation requirements, taking into account both simulation accuracy and stability.
[0063] When the stabilizing factor 1, precision factor When the stability factor is 0, the discretization equations are equivalent to the discretization modeling by the backward Euler method. 0.5, precision factor When the stability factor is 0.5, the discretized equations are equivalent to the discretized modeling by the trapezoidal integration method. 0, precision factor When it is 1, the discretized equations are equivalent to discretized modeling using the forward Euler method.
[0064] Step S3: sort out the discretized equation group to obtain the target equation group.
[0065] It should be noted that the discretized equations obtained in step S2 are sorted out, and the current parameters and voltage parameters in the state variable matrix X and the matrix of other variables other than the state variables U are placed on both sides of the equation to obtain the target equations: ,in, is the current of all branches connected to the power electronic converter. is the voltage of all nodes connected to the outside of the power electronic converter, is the equivalent admittance matrix of the power electronic converter, is the historical current source of the power electronic converter.
[0066] Step S4: Based on the target equation group, solve the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter, and send the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter to the electromagnetic transient solver, so that the electromagnetic transient solver completes the electromagnetic transient simulation modeling of the power electronic converter.
[0067] It should be noted that according to the target equations Solving the Equivalent Admittance Matrix of Power Electronic Converters and historical current sources for power electronic converters The electromagnetic transient solver is based on the equivalent admittance matrix of the power electronic converter. and historical current sources for power electronic converters , calculate the latest node voltage of the current simulation step, and complete the electromagnetic transient simulation modeling of the power electronic converter. The solution process of the electromagnetic transient solver is existing technology and will not be repeated here.
[0068] The effect of using the electromagnetic transient simulation modeling method of the power electronic converter provided by the present invention and the conventional trapezoidal integration method to model and simulate the three-phase bridge converter is compared. Figure 3 As shown in the figure, it can be seen that the converter node voltage shows an oscillating divergence trend under the trapezoidal integration method modeling method. The stability factor and precision factor introduced by this method can effectively avoid the node voltage divergence and improve the high simulation stability and accuracy.
[0069] The electromagnetic transient simulation modeling method for a power electronic converter provided by the present invention establishes a differential equation system for the power electronic converter, introduces a stability factor and a precision factor to discretize the differential equation system for the power electronic converter, and then solves the target equation system obtained by discretization. The electromagnetic transient simulation modeling of the power electronic converter is completed by an electromagnetic transient solver. During the electromagnetic transient simulation modeling process of the power electronic converter, the stability factor and precision factor in the discretization of the converter modeling can be flexibly set according to different application scenarios and simulation requirements, effectively balancing the stability and precision of the simulation, thereby solving the technical problem that the existing electromagnetic transient simulation modeling of the power electronic converter is difficult to balance the stability and precision of the electromagnetic transient simulation modeling of the power electronic converter.
[0070] For easier understanding, see Figure 4 The present invention provides an embodiment of an electromagnetic transient simulation modeling device for a power electronic converter, comprising:
[0071] The differential equation building block is used to build the differential equations of the power electronic converter. The differential equations of the power electronic converter are , where X is the state variable matrix, is the differential of X, U is the matrix of other variables except the state variables, A, B, and C are the first coefficient matrix, the second coefficient matrix, and the third coefficient matrix respectively. The state variables include: the branch current where the AC measuring inductor of the power electronic converter is located and the voltage of the node connected to the DC side capacitor of the power electronic converter;
[0072] The discretization module is used to configure the stability factor and precision factor for the differential equation group of the power electronic converter, discretize the differential equation group of the power electronic converter, and obtain the discretized equation group: ,in, is discrete time, is the state variable at the current moment, is the state variable at the previous moment, are other variables at the current moment, are other variables at the previous moment, 、 、 、 are the first discretization coefficient matrix, the second discretization coefficient matrix, the third discretization coefficient matrix and the fourth discretization coefficient matrix obtained by discretization respectively, is the stabilizing factor, is the precision factor;
[0073] The adjustment module is used to sort out the discretized equations to obtain the target equations: ,in, is the current of all branches connected to the power electronic converter. is the voltage of all nodes connected to the outside of the power electronic converter, is the equivalent admittance matrix of the power electronic converter, is the historical current source of the power electronic converter;
[0074] The solving module is used to solve the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter based on the target equation group, and send the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter to the electromagnetic transient solver, so that the electromagnetic transient solver completes the electromagnetic transient simulation modeling of the power electronic converter.
[0075] In one embodiment, the first discretization coefficient matrix is:
[0076]
[0077] The second discretization coefficient matrix is:
[0078]
[0079] The third discretization coefficient matrix is:
[0080]
[0081] The fourth discretization coefficient matrix is:
[0082] .
[0083] In one embodiment, the stability factor and the precision factor meet the preset conditions, which are: .
[0084] In one embodiment, the stability factor ranges from 0 to 1, and the precision factor ranges from 0 to 1.
[0085] For easier understanding, see Figure 5 The present invention provides an embodiment of a power electronic converter electromagnetic transient simulation modeling device, the device comprising a processor and a memory:
[0086] The memory is used to store program code and transmit the program code to the processor;
[0087] The processor is used to execute any one of the electromagnetic transient simulation modeling methods for power electronic converters provided in the embodiments of the electromagnetic transient simulation modeling method for power electronic converters according to the instructions in the program code.
[0088] The present invention provides an embodiment of a computer-readable storage medium, which is used to store program code, and the program code is used to execute any one of the power electronic converter electromagnetic transient simulation modeling method embodiments provided in the present invention.
[0089] The electromagnetic transient simulation modeling device, equipment and computer-readable storage medium of the power electronic converter provided in the present invention are all used to execute the electromagnetic transient simulation modeling method of the power electronic converter provided in the present invention. The principles and technical effects achieved are the same as those of the electromagnetic transient simulation modeling method of the power electronic converter provided in the present invention, and will not be repeated here.
[0090] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.
[0091] As described above, 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 above embodiments, those skilled in the art should understand that the technical solutions described in the above 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 electromagnetic transient simulation modeling of a power electronic converter, characterized in that: include: Establish the differential equations of the power electronic converter. The differential equations of the power electronic converter are: , where X is the state variable matrix, is the differential of X, U is the matrix of other variables except the state variables, A, B, and C are the first coefficient matrix, the second coefficient matrix, and the third coefficient matrix respectively. The state variables include: the branch current where the AC measuring inductor of the power electronic converter is located and the voltage of the node connected to the DC side capacitor of the power electronic converter; Configure the stability factor and precision factor for the differential equations of the power electronic converter, discretize the differential equations of the power electronic converter, and obtain the discretized equations: ,in, is discrete time, is the state variable at the current moment, is the state variable at the previous moment, are other variables at the current moment, are other variables at the previous moment, 、 、 、 are the first discretization coefficient matrix, the second discretization coefficient matrix, the third discretization coefficient matrix and the fourth discretization coefficient matrix obtained by discretization respectively, is the stabilizing factor, is the precision factor; Arrange the discretized equations to obtain the target equations: ,in, is the current of all branches connected to the power electronic converter. is the voltage of all nodes connected to the outside of the power electronic converter, is the equivalent admittance matrix of the power electronic converter, is the historical current source of the power electronic converter; Based on the target equation group, the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter are solved, and the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter are sent to the electromagnetic transient solver, so that the electromagnetic transient solver completes the electromagnetic transient simulation modeling of the power electronic converter.
2. The electromagnetic transient simulation modeling method for power electronic converter according to claim 1, characterized in that: The first discretization coefficient matrix is: The second discretization coefficient matrix is: The third discretization coefficient matrix is: The fourth discretization coefficient matrix is: 。 3. The electromagnetic transient simulation modeling method for power electronic converter according to claim 1, characterized in that: The stability factor and precision factor meet the pre-conditions, which are: .
4. The electromagnetic transient simulation modeling method for power electronic converter according to claim 3, characterized in that: The stability factor ranges from 0 to 1, and the precision factor ranges from 0 to 1.
5. A power electronic converter electromagnetic transient simulation modeling device, characterized in that: include: The differential equation building block is used to build the differential equations of the power electronic converter. The differential equations of the power electronic converter are , where X is the state variable matrix, is the differential of X, U is the matrix of other variables except the state variables, A, B, and C are the first coefficient matrix, the second coefficient matrix, and the third coefficient matrix respectively. The state variables include: the branch current where the AC measuring inductor of the power electronic converter is located and the voltage of the node connected to the DC side capacitor of the power electronic converter; The discretization module is used to configure the stability factor and precision factor for the differential equation group of the power electronic converter, discretize the differential equation group of the power electronic converter, and obtain the discretized equation group: ,in, is discrete time, is the state variable at the current moment, is the state variable at the previous moment, are other variables at the current moment, are other variables at the previous moment, 、 、 、 are the first discretization coefficient matrix, the second discretization coefficient matrix, the third discretization coefficient matrix and the fourth discretization coefficient matrix obtained by discretization respectively, is the stabilizing factor, is the precision factor; The adjustment module is used to sort out the discretized equations to obtain the target equations: ,in, is the current of all branches connected to the power electronic converter. is the voltage of all nodes connected to the outside of the power electronic converter, is the equivalent admittance matrix of the power electronic converter, is the historical current source of the power electronic converter; The solving module is used to solve the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter based on the target equation group, and send the equivalent admittance matrix of the power electronic converter and the historical current source of the power electronic converter to the electromagnetic transient solver, so that the electromagnetic transient solver completes the electromagnetic transient simulation modeling of the power electronic converter.
6. The electromagnetic transient simulation modeling device for a power electronic converter according to claim 5, characterized in that: The first discretization coefficient matrix is: The second discretization coefficient matrix is: The third discretization coefficient matrix is: The fourth discretization coefficient matrix is: 。 7. The electromagnetic transient simulation modeling device for a power electronic converter according to claim 5, characterized in that: The stability factor and precision factor meet the pre-conditions, which are: .
8. The electromagnetic transient simulation modeling device for a power electronic converter according to claim 7, characterized in that: The stability factor ranges from 0 to 1, and the precision factor ranges from 0 to 1.
9. A power electronic converter electromagnetic transient simulation modeling device, characterized in that: The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the electromagnetic transient simulation modeling method of a power electronic converter according to any one of claims 1 to 4 according to the instructions in the program code.
10. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store program code, and the program code is used to execute the electromagnetic transient simulation modeling method for a power electronic converter according to any one of claims 1 to 4.