Method and device for rapidly solving port voltage and current of BCTRAN model
By constructing the transient admittance equation and identifying boundary conditions of the BCTRAN model, using phasor method and matrix theory to solve the transformer port current and voltage, the long simulation time and software dependence problems of BCTRAN model are solved, and rapid solution and extensive adaptation are achieved, and rapid simulation of transformer short-circuit faults is supported.
Patent Information
- Application Number
- CN202510546508.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-28
- Publication Date
- 2025-08-01
AI Technical Summary
The port voltage and current solution method of the existing BCTRAN model has a long simulation time and relies on professional electromagnetic transient simulation software, which cannot be adapted on multiple software platforms, making it difficult to meet the rapid simulation requirements of transformer short circuit faults.
By constructing the transient admittance equation of the BCTRAN model, the boundary conditions of each port of the transformer are identified, and the steady-state and transient solutions are solved respectively using the phasor method and matrix theory. Combined with the boundary conditions, the current and voltage of each port of the transformer are quickly solved.
It realizes rapid solution of the BCTRAN model, reduces simulation time, reduces dependence on professional electromagnetic transient simulation software, expands its applicability in a variety of software platforms, and supports rapid simulation of transformer short-circuit faults.
Smart Images
Figure CN120409019A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of transformers, and in particular to a method and device for quickly solving port voltage and current of a BCTRAN model. Background Art
[0002] Transformers are core equipment in power systems, and their short-circuit faults are one of the most common and serious types of accidents. The BCTRAN model is a commonly used model for transformer short-circuit fault simulation. This model describes the coupling relationship between windings through a set of high-dimensional inductance matrices and is suitable for transient simulation of multi-winding transformers. Some electromagnetic transient simulation software has built-in BCTRAN models that can be directly called, but the use of built-in models is highly dependent on professional electromagnetic transient simulation software and cannot be used with other simulation software. In addition, the BCTRAN model can also be obtained by compiling the code and using the complex frequency domain method, but the complex frequency domain solution method has the disadvantage of long simulation time and is not suitable for rapid analysis of short-circuit faults. Therefore, providing a reasonable and effective method for quickly solving the port voltage and current of the BCTRAN model to reduce simulation time and expand its adaptability on multiple software platforms, providing an effective way to quickly simulate transformer short-circuit faults, is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention
[0003] The present invention provides a method and device for quickly solving the port voltage and current of a BCTRAN model, which is used to quickly solve the port voltage and current of a BCTRAN model, reduce simulation time and dependence on professional electromagnetic transient simulation software, and provide an effective way to quickly simulate transformer short-circuit faults.
[0004] In view of this, the first aspect of the present invention provides a method for quickly solving port voltage and current of a BCTRAN model, comprising:
[0005] Construct the transient admittance equation of the BCTRAN model;
[0006] According to the actual operating conditions of the transformer, the boundary conditions of each transformer port are identified. The transformer ports are divided into the excitation end, the load end, the open circuit end and the short circuit end according to the operating conditions.
[0007] Solve the steady-state solution of the current at each port of the transformer based on the phasor method;
[0008] Solve the transient solution of the current at each port of the transformer based on matrix theory;
[0009] Add the steady-state solution and transient solution of the current at each port of the transformer to obtain the complete solution of the current at each port of the transformer;
[0010] Based on the complete solution of the current at each port of the transformer, the voltage at each port of the transformer is solved.
[0011] Optionally, the transient admittance equation of the BCTRAN model is:
[0012]
[0013] where is the first derivative of the current at the i-th port of the transformer, is the voltage at the i-th port of the transformer, is the element in the i-th row and j-th column of the admittance matrix, is the current at the i-th port of the transformer, is the winding resistance of the i-th port of the transformer, , , and n is the total number of transformer ports.
[0014] Optionally, solving the steady-state solutions of the currents at all ports of the transformer based on the phasor method includes:
[0015] Converting the transient admittance equation of the BCTRAN model into phasor form;
[0016] Performing a phase shift on the voltage-current matrix in the transient admittance equation of the BCTRAN model in phasor form to separate the known and unknown quantities, where the known and unknown quantities are determined according to the boundary conditions of all ports of the transformer;
[0017] Solving for the unknown quantity matrix according to matrix division to obtain the steady-state solutions of the currents at all ports of the transformer.
[0018] Optionally, solving the transient solutions of the currents at all ports of the transformer based on matrix theory includes:
[0019] Writing out the homogeneous constant coefficient differential equation set of the BCTRAN model according to the transient admittance equation of the BCTRAN model;
[0020] Obtaining the general solution formula for solving the homogeneous constant coefficient differential equation set of the BCTRAN model based on matrix theory;
[0021] Obtaining the initial values of the quantities to be solved for the homogeneous constant coefficient differential equation set based on the boundary conditions of all ports of the transformer, and solving the transient solutions of the currents at all ports of the transformer, where the initial values of the quantities to be solved are the initial values of the port currents.
[0022] Optionally, solving the voltages at all ports of the transformer based on the complete solutions of the currents at all ports of the transformer includes:
[0023] Substituting the complete solutions of the currents at all ports of the transformer into the transient admittance equation of the BCTRAN model to obtain the voltages at all ports of the transformer.
[0024] A second aspect of the present invention provides a device for quickly solving port voltage and current of a BCTRAN model, comprising:
[0025] Admittance equation building module, used to build the transient admittance equation of the BCTRAN model;
[0026] A boundary identification module is used to identify the boundary conditions of each transformer port according to the actual operating conditions of the transformer. The transformer ports are divided into an excitation port, a load port, an open circuit port, and a short circuit port according to the operating conditions.
[0027] The port current steady-state solution module is used to solve the steady-state solution of each port current of the transformer based on the phasor method;
[0028] The port current transient solution module is used to solve the transient solution of each port current of the transformer based on matrix theory;
[0029] The port current complete solution module is used to add the steady-state solution and transient solution of each transformer port current to obtain the complete solution of each transformer port current;
[0030] The port voltage solving module is used to solve the voltage of each port of the transformer based on the complete solution of the current of each port of the transformer.
[0031] Alternatively, the transient admittance equation of the BCTRAN model is:
[0032]
[0033] in, is the first-order derivative of the current at the ith port of the transformer, is the voltage at the ith port of the transformer, is the element in row i and column j of the admittance matrix, is the current of the transformer’s ith port, is the winding resistance of the transformer at the i-th port, , , n is the total number of transformer ports.
[0034] Optionally, the port current steady-state solution module is specifically used to:
[0035] Convert the transient admittance equation of the BCTRAN model into phasor form;
[0036] The voltage and current matrices in the transient admittance equation of the BCTRAN model in phasor form are phase-shifted to separate known and unknown quantities, where the known and unknown quantities are determined based on the boundary conditions of each port of the transformer.
[0037] The matrix of unknown quantities is solved by matrix division to obtain the steady-state solution of the current at each port of the transformer.
[0038] Optionally, the port current transient solution module is specifically configured to:
[0039] According to the transient admittance equation of the BCTRAN model, list the homogeneous constant coefficient differential equation group of the BCTRAN model;
[0040] Based on matrix theory, obtain the general solution formula for solving the homogeneous constant coefficient differential equation group of the BCTRAN model;
[0041] Based on the boundary conditions of each port of the transformer, obtain the initial values of the quantities to be solved in the homogeneous constant coefficient differential equation group, and solve the transient solutions of the currents at each port of the transformer, where the initial values of the quantities to be solved are the initial values of the port currents.
[0042] Optionally, the port voltage solution module is specifically configured to:
[0043] Substitute the complete solutions of the currents at each port of the transformer into the transient admittance equation of the BCTRAN model to obtain the voltages at each port of the transformer.
[0044] From the above technical solutions, it can be seen that the method for quickly solving the port voltage and current of the BCTRAN model provided by the present invention has the following advantages:
[0045] The method for quickly solving the port voltage and current of the BCTRAN model provided by the present invention is based on the transient admittance equation of the BCTRAN model and the boundary conditions of each port of the transformer, and respectively solves the steady-state solutions of the currents at each port, the transient solutions of the currents at each port of the transformer, obtains the complete solutions of the currents at each port of the transformer, and then solves the voltages at each port of the transformer based on the complete solutions of the currents at each port of the transformer. Compared with the traditional complex frequency domain solution method of the BCTRAN model, the method for quickly solving the port voltage and current of the BCTRAN model provided by the present invention has an absolute simulation speed advantage, realizes the quick solution of the BCTRAN model, can be implemented through programming code, has excellent software adaptability, reduces the dependence on professional electromagnetic transient simulation software, achieves the technical effect of quickly solving the port voltage and current of the BCTRAN model, reducing the simulation time and the dependence on professional electromagnetic transient simulation software, and providing an effective way for the quick simulation of transformer short-circuit faults. Description of the Drawings
[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.
[0047] Figure 1Schematic flowchart of a method for quickly solving port voltage and current of a BCTRAN model provided in an embodiment of the present invention;
[0048] Figure 2 Schematic structural diagram of a device for quickly solving port voltage and current of a BCTRAN model provided in an embodiment of the present invention. Detailed implementation manners
[0049] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0050] For ease of understanding, please refer to Figure 1 , the present invention provides an embodiment of a method for quickly solving port voltage and current of a BCTRAN model, including:
[0051] Step 101: Construct a transient admittance equation of the BCTRAN model.
[0052] It should be noted that in the embodiment of the present invention, the transient admittance equation of the BCTRAN model is first written. The transient admittance equation of the BCTRAN model represents the relationship between the voltages and currents of multiple windings of the transformer.
[0053] When the influence of winding resistance is not considered, the transient admittance equation of the BCTRAN model is expressed as:
[0054]
[0055]
[0056] Wherein, is the first derivative of the current of the i-th port of the transformer, is the voltage of the i-th port of the transformer, is the admittance matrix, can be obtained from the self and mutual inductance matrix , the self and mutual inductance matrix is a known quantity, and the relationship between the admittance matrix and the self and mutual inductance matrix is , is the element in the i-th row and j-th column of the admittance matrix, , , and n is the total number of transformer ports.
[0057] When considering the winding resistance, the transient admittance equation of the BCTRAN model is expressed as:
[0058]
[0059] Wherein, is the current of the i-th port of the transformer, is the winding resistance of the i-th port of the transformer.
[0060] The transient admittance equation of the BCTRAN model when considering the winding resistance can be simplified to:
[0061]
[0062]
[0063] Wherein, is the coefficient matrix.
[0064] Step 102: Identify the boundary conditions of each port of the transformer according to the actual operating conditions of the transformer. Among them, the ports of the transformer are divided into an excitation end, a load end, an open circuit end, and a short circuit end according to the operating conditions.
[0065] It should be noted that the ports of the transformer are divided into an excitation end, a load end, an open circuit end, and a short circuit end according to the operating conditions. The voltage at the excitation end is the power supply voltage. The following relationship exists at the load end: , where U is the voltage, I is the current, and R is the load resistance. The current at the open circuit end is 0, and the voltage at the short circuit end is 0. Distinguish the boundary conditions of each port according to the actual operating conditions of the transformer to reduce the number of unknowns in the BCTRAN model.
[0066] Step 103: Solve the steady-state solution of the current of each port of the transformer based on the phasor method.
[0067] It should be noted that the transient admittance equation of the BCTRAN model after the above simplification when considering the winding resistance is a non-homogeneous constant coefficient differential equation system with respect to the variable . When solving, it is necessary to solve the general solution of the homogeneous constant coefficient differential equation system and the particular solution of the non-homogeneous constant coefficient differential equation system respectively, and the sum of the two can obtain the complete solution of the non-homogeneous constant coefficient differential equation system.
[0068] The general solution of the homogeneous constant coefficient differential equation system is:
[0069]
[0070] Wherein, A is the coefficient of the general solution of the homogeneous equation, is the characteristic root of the homogeneous equation, and t is the time variable.
[0071] The particular solution of the non - homogeneous constant - coefficient differential equation system is as follows:
[0072]
[0073] Among them, the particular solution of the non - homogeneous constant - coefficient differential equation system consists of an exponential term and a sine term. B is the coefficient of the exponential term, C is the amplitude of the sine term, is the angular frequency, is the phase.
[0074] Adding the general solution of the homogeneous constant - coefficient differential equation system and the particular solution of the non - homogeneous constant - coefficient differential equation system can obtain the complete solution of the non - homogeneous constant - coefficient differential equation system:
[0075]
[0076] From the expression of the complete solution of the above non - homogeneous constant - coefficient differential equation system, it can be seen that the port current is composed of a sine component and an exponential component. Among them, the sine component corresponds to the steady - state solution of the port current, and the exponential component corresponds to the transient solution of the port current.
[0077] In the embodiments of the present invention, first, the steady - state solutions of the port currents are solved. The steady - state solutions of the port currents can be solved by the phasor method. Specifically, the transient admittance equation of the BCTRAN model is converted into phasor form. The phasor form of the transient admittance equation of the BCTRAN model without considering the influence of winding resistance is:
[0078]
[0079]
[0080] Among them, is the phasor form of the current of the i - th port of the transformer, is the phasor form of the voltage of the i - th port of the transformer. The matrix can be obtained from the self - mutual inductance matrix The self - mutual inductance matrix is a known quantity, and the relationship between the admittance matrix and the self - mutual inductance matrix is .
[0081] The phasor form of the transient admittance equation of the BCTRAN model considering winding resistance is:
[0082]
[0083]
[0084] Simplifying the above phasor form of the transient admittance equation of the BCTRAN model considering winding resistance, we can get:
[0085]
[0086]
[0087] Matrix The calculation formula of is as follows:
[0088]
[0089] Among them, E is the identity matrix.
[0090] Perform a phase shift on the voltage and current matrices in the transient admittance equation of the BCTRAN model in phasor form to separate the known and unknown quantities. Among them, the known and unknown quantities are determined according to the boundary conditions of each port of the transformer. For the voltage matrix and the current matrix perform a phase shift process to separate the known and unknown quantities in the matrix, and the following formula is obtained:
[0091]
[0092] Among them, A is the coefficient matrix, B is the known quantity matrix, and X is the unknown quantity matrix after phase shift.
[0093] Solve the unknown quantity matrix according to matrix division X = B / A to obtain the steady-state solution of the current at each port of the transformer.
[0094] Step 104: Solve the transient solution of the current at each port of the transformer based on matrix theory.
[0095] It should be noted that based on the simplified transient admittance equation of the BCTRAN model considering winding resistance, write out the homogeneous constant coefficient differential equation group of the BCTRAN model:
[0096]
[0097] According to matrix theory, the general solution formula for solving the homogeneous constant coefficient differential equation group is:
[0098]
[0099] Among them, matrix X is the quantity to be solved, matrix X0 is the initial value of the quantity to be solved, and matrix D is the coefficient matrix of the homogeneous constant coefficient differential equation.
[0100] From it can be seen that obtaining the solution of this formula requires obtaining the coefficient matrix of the homogeneous constant coefficient differential equation group and the initial value of the quantity to be solved. Matrix D is the coefficient matrix . The initial value of the quantity to be solved is the initial value of the port current. The initial value of the port current can be obtained from the boundary conditions identified in step 102. Take the coefficient matrix Substitute the initial values of the port current into to obtain The solution formula for
[0101]
[0102] where the matrix I is the port current, and the matrix is the initial value of the port current.
[0103] Based on the transient solution of the port current can be solved.
[0104] Step 105: Add the steady-state solution and the transient solution of the port currents of each transformer to obtain the complete solution of the port currents of each transformer.
[0105] It should be noted that by adding the steady-state solution and the transient solution of the port currents of each transformer, the complete solution of the port currents of each transformer can be obtained.
[0106] Step 106: Solve the port voltages of each transformer based on the complete solution of the port currents of each transformer.
[0107] It should be noted that substitute the complete solution of the port currents of each transformer obtained in Step 105 into the transient admittance equation of the BCTRAN model. Generally, substitute it into the transient admittance equation of the BCTRAN model considering the winding resistance after simplification to solve the port voltages of each transformer.
[0108] To verify the correctness of the method for quickly solving the port voltage and current of the BCTRAN model provided in the present invention, in the present invention, for the same BCTRAN model, the program codes of Steps 101 to 105 are written in Matlab. Compare the method for quickly solving the port voltage and current of the BCTRAN model provided in the present invention with the conventional complex frequency domain solution method, and compare the solution results and solution times of the two to verify the correctness and rapidity of the method proposed in the present invention. The present invention conducts a simulation comparison for a 12th-order BCTRAN model, and the simulation time is set as follows: time step 1e-4 s, simulation duration 0.06 s. The complex frequency domain model solution takes 42 minutes and 16 seconds, while the method proposed in the present invention only takes 0.259 s, which greatly improves the simulation speed. In addition, the simulation results of the two are basically the same, proving the correctness and efficiency of the method proposed in the present invention.
[0109] The method for quickly solving the port voltage and current of the BCTRAN model provided by the present invention is based on the transient admittance equation of the BCTRAN model and the boundary conditions of each port of the transformer. It separately solves the steady-state solution of the current of each port and the transient solution of the current of each port of the transformer to obtain the complete solution of the current of each port of the transformer, and then solves the port voltage of the transformer based on the complete solution of the current of each port of the transformer. Compared with the traditional complex frequency domain solution method of the BCTRAN model, the method for quickly solving the port voltage and current of the BCTRAN model provided by the present invention has an absolute simulation speed advantage, realizes the quick solution of the BCTRAN model, can be implemented through programming code, has excellent software adaptability, reduces the dependence on professional electromagnetic transient simulation software, achieves the technical effect of quickly solving the port voltage and current of the BCTRAN model, reducing the simulation time and the dependence on professional electromagnetic transient simulation software, and providing an effective way for the quick simulation of transformer short-circuit faults.
[0110] For ease of understanding, please refer to Figure 2 , an embodiment of a device for quickly solving the port voltage and current of a BCTRAN model provided in the present invention includes:
[0111] An admittance equation construction module for constructing the transient admittance equation of the BCTRAN model;
[0112] A boundary recognition module for identifying the boundary conditions of each port of the transformer according to the actual operating conditions of the transformer, where the ports of the transformer are divided into an excitation end, a load end, an open end, and a short-circuit end according to the operating conditions;
[0113] A port current steady-state solution module for solving the steady-state solution of the current of each port of the transformer based on the phasor method;
[0114] A port current transient solution module for solving the transient solution of the current of each port of the transformer based on matrix theory;
[0115] A port current complete solution module for adding the steady-state solution and the transient solution of the current of each port of the transformer to obtain the complete solution of the current of each port of the transformer;
[0116] A port voltage solution module for solving the port voltage of the transformer based on the complete solution of the current of each port of the transformer.
[0117] In one embodiment, the transient admittance equation of the BCTRAN model is:
[0118]
[0119] Wherein, is the first derivative of the current of the i-th port of the transformer, is the voltage of the i-th port of the transformer, is the element in the i-th row and j-th column of the admittance matrix, is the current of the i-th port of the transformer, is the winding resistance of the i-th port of the transformer, , , where n is the total number of transformer ports.
[0120] In one embodiment, the port current steady-state solution module is specifically configured to:
[0121] Convert the transient admittance equation of the BCTRAN model into a phasor form;
[0122] Perform a phase shift on the voltage-current matrix in the transient admittance equation of the phasor form of the BCTRAN model to separate known and unknown quantities, where the known and unknown quantities are determined according to the boundary conditions of each port of the transformer;
[0123] Solve the unknown quantity matrix according to matrix division to obtain the steady-state solutions of the currents of each port of the transformer.
[0124] In one embodiment, the port current transient solution module is specifically configured to:
[0125] Write out the homogeneous constant coefficient differential equation group of the BCTRAN model according to the transient admittance equation of the BCTRAN model;
[0126] Obtain the general solution solving formula of the homogeneous constant coefficient differential equation group of the BCTRAN model based on matrix theory;
[0127] Obtain the initial values of the quantities to be solved of the homogeneous constant coefficient differential equation group based on the boundary conditions of each port of the transformer, and solve the transient solutions of the currents of each port of the transformer, where the initial values of the quantities to be solved are the initial values of the port currents.
[0128] In one embodiment, the port voltage solution module is specifically configured to:
[0129] Substitute the complete solutions of the currents of each port of the transformer into the transient admittance equation of the BCTRAN model to obtain the voltages of each port of the transformer.
[0130] The port voltage and current fast solution device of the BCTRAN model provided in the present invention is used to execute the port voltage and current fast solution method of the BCTRAN model provided in the present invention. Its principle and the achieved technical effects are the same as those of the port voltage and current fast solution method of the BCTRAN model provided in the present invention, and will not be elaborated here.
[0131] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for quickly solving the port voltage and current of a BCTRAN model, characterized in that Including: Construct the transient admittance equation of the BCTRAN model; According to the actual operating conditions of the transformer, identify the boundary conditions of each port of the transformer. Among them, the ports of the transformer are divided into the excitation end, the load end, the open circuit end and the short circuit end according to the operating conditions; Based on the phasor method, solve the steady-state solution of the current of each port of the transformer; Based on matrix theory, solve the transient solution of the current of each port of the transformer; Add the steady-state solution and the transient solution of the current of each port of the transformer to obtain the complete solution of the current of each port of the transformer; Based on the complete solution of the current of each port of the transformer, solve the voltage of each port of the transformer.
2. The method for quickly solving the port voltage and current of the BCTRAN model according to claim 1, characterized in that, The transient admittance equation of the BCTRAN model is: Among them, is the first derivative of the current at the i-th port of the transformer, is the voltage at the i-th port of the transformer, is the element in the i-th row and j-th column of the admittance matrix, is the current at the i-th port of the transformer, is the winding resistance of the i-th port of the transformer, , , and n is the total number of transformer ports.
3. The method for quickly solving the port voltage and current of the BCTRAN model according to claim 2, wherein, Based on the phasor method to solve the steady-state solution of the current of each port of the transformer, including: Convert the transient admittance equation of the BCTRAN model into phasor form; Perform a phase shift transformation on the voltage-current matrix in the phasor form of the transient admittance equation of the BCTRAN model to separate the known quantities and the unknown quantities, where the known quantities and the unknown quantities are determined according to the boundary conditions of each port of the transformer; Solve the unknown quantity matrix according to matrix division to obtain the steady-state solution of the current of each port of the transformer.
4. The method for quickly solving the port voltage and current of the BCTRAN model according to claim 3, wherein Based on matrix theory to solve the transient solution of the current of each port of the transformer, including: According to the transient admittance equation of the BCTRAN model, list the homogeneous constant coefficient differential equation group of the BCTRAN model; Based on matrix theory, obtain the general solution solving formula of the homogeneous constant coefficient differential equation group of the BCTRAN model; Based on the boundary conditions of each port of the transformer, obtain the initial value of the quantity to be solved of the homogeneous constant coefficient differential equation group, and solve the transient solution of the current of each port of the transformer, where the initial value of the quantity to be solved is the initial value of the port current.
5. The method for quickly solving the port voltage and current of the BCTRAN model according to claim 4, wherein Based on the complete solution of the current of each port of the transformer, solve the voltage of each port of the transformer, including: Substitute the complete solution of the current of each port of the transformer into the transient admittance equation of the BCTRAN model to obtain the voltage of each port of the transformer.
6. A device for quickly solving the port voltage and current of a BCTRAN model, characterized in that, Including: The admittance equation construction module is used to construct the transient admittance equation of the BCTRAN model; The boundary identification module is used to identify the boundary conditions of each port of the transformer according to the actual operating conditions of the transformer. Among them, the ports of the transformer are divided into the excitation end, the load end, the open circuit end and the short circuit end according to the operating conditions; The port current steady-state solution module is used to solve the steady-state solution of the current of each port of the transformer based on the phasor method; The port current transient solution module is used to solve the transient solution of the current of each port of the transformer based on matrix theory; The port current complete solution module is used to add the steady-state solution and the transient solution of the current of each port of the transformer to obtain the complete solution of the current of each port of the transformer; The port voltage solution module is used to solve the voltage of each port of the transformer based on the complete solution of the current of each port of the transformer.
7. The port voltage and current fast solving device of the BCTRAN model according to claim 6, characterized in that, The transient admittance equation of the BCTRAN model is: wherein, is the first derivative of the current of the i-th port of the transformer, is the voltage of the i-th port of the transformer, is the element in the i-th row and j-th column of the admittance matrix, is the current of the i-th port of the transformer, is the winding resistance of the i-th port of the transformer, , , and n is the total number of ports of the transformer.
8. The port voltage and current fast solution device of the BCTRAN model according to claim 7, characterized in that, The port current steady-state solution module is specifically used for: Convert the transient admittance equation of the BCTRAN model into phasor form; Perform a phase shift transformation on the voltage-current matrix in the phasor form of the transient admittance equation of the BCTRAN model to separate the known quantities and the unknown quantities, where the known quantities and the unknown quantities are determined according to the boundary conditions of each port of the transformer; Solve the unknown matrix according to matrix division to obtain the steady-state solutions of the currents at each port of the transformer.
9. The port voltage and current rapid solution device of the BCTRAN model according to claim 8, characterized in that The transient current solving module at the port is specifically used for: According to the transient admittance equation of the BCTRAN model, list the homogeneous constant coefficient differential equation system of the BCTRAN model; Based on matrix theory, obtain the general solution solving formula of the homogeneous constant coefficient differential equation system of the BCTRAN model; Based on the boundary conditions at each port of the transformer, obtain the initial values of the quantities to be solved of the homogeneous constant coefficient differential equation system, and solve the transient solutions of the currents at each port of the transformer, where the initial values of the quantities to be solved are the initial values of the port currents.
10. The device for quickly solving the port voltage and current of the BCTRAN model according to claim 9, characterized in that, The port voltage solving module is specifically used for: Substitute the complete solutions of the currents at each port of the transformer into the transient admittance equation of the BCTRAN model to obtain the voltages at each port of the transformer.