Electric reactor fault diagnosis simulation method, device and equipment and storage medium

Abstract

The invention discloses an electric reactor fault diagnosis simulation method, device and equipment and a storage medium, and the method comprises the steps: obtaining the recording data of a to-be-detected electric reactor during a fault, and applying an excitation signal to the electric reactor according to the recording data; constructing a two-dimensional axisymmetric electromagnetic field model based on the reactor structure of the reactor to be detected, and calculating the two-dimensional axisymmetric electromagnetic field model to obtain a resistance matrix and an inductance matrix of the reactor to be detected; constructing a three-dimensional electrostatic field model according to a coil winding structure in the reactor to be detected, solving the three-dimensional electrostatic field model to obtain a Maxwell capacitance matrix, and constructing a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix; and solving and processing the multi-conductor transmission line equivalent model to obtain a fault diagnosis result of the reactor to be detected. According to the method, the reactor coil winding is equivalent to the multi-conductor transmission line for simulation calculation, so that the fault diagnosis accuracy of the reactor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment status assessment, and in particular to a reactor fault diagnosis simulation method, device, equipment and storage medium. Background Art

[0002] As one of the important equipment in the DC converter station, the dry-type air-core reactor can prevent the steep voltage waves generated by the DC line side or the DC switch from entering the high-voltage valve hall, thus avoiding damage to the converter valve due to overvoltage. It has a smoothing and suppressing effect on the ripple in the DC current, can avoid current discontinuity when the transmission load is small, and can effectively reduce the commutation failure rate. At present, with the continuous expansion of the scale of UHV DC transmission of the State Grid, the number of reactors used in the power system is increasing year by year.

[0003] However, the failure mechanism of dry-type air-core reactors is still unclear, and the existing fault monitoring technology has not been widely promoted and applied because its performance cannot meet the demand, making it difficult to achieve real-time perception of the reactor's operating status. In addition, due to the particularity of the dry-type reactor's "dressing and wearing a hat" structural design, some of its monitoring data is difficult to obtain or there are monitoring errors, and it is urgent to improve the simulation method for reactor fault diagnosis. Summary of the invention

[0004] In order to solve the above technical problems, an embodiment of the present invention provides a reactor fault diagnosis simulation method, device, equipment and storage medium, which solves the problem that the existing reactor fault monitoring technology is difficult to monitor and it is difficult to accurately judge the reactor fault due to the particularity of the reactor structure design.

[0005] A first aspect of an embodiment of the present invention provides a reactor fault diagnosis simulation method, the method comprising:

[0006] Acquire the recorded wave data of the reactor to be detected when it fails, and apply an excitation signal to the reactor according to the recorded wave data, wherein the excitation signal includes a DC component and an AC component;

[0007] A two-dimensional axisymmetric electromagnetic field model is constructed based on the reactor structure of the reactor to be detected, and the two-dimensional axisymmetric electromagnetic field model is calculated to obtain a resistance matrix and an inductance matrix of the reactor to be detected;

[0008] A three-dimensional electrostatic field model is constructed according to the coil winding structure in the reactor to be tested, the three-dimensional electrostatic field model is solved to obtain a Maxwell capacitance matrix, and a multi-conductor transmission line equivalent model is constructed according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix;

[0009] The main operating frequency is determined based on the excitation signal. According to the main operating frequency, the equivalent model of the multi-conductor transmission line is solved to obtain the reactance waves at different positions of the coil winding in the inductor to be tested. The features in each reactance wave are extracted to obtain the feature extraction result. The feature quantity is compared with the ripple level under normal conditions to obtain the fault diagnosis result of the inductor to be tested.

[0010] In a possible implementation of the first aspect, a two-dimensional axisymmetric electromagnetic field model is constructed based on the reactor structure of the reactor to be detected, and the two-dimensional axisymmetric electromagnetic field model is calculated to obtain a resistance matrix and an inductance matrix of the reactor to be detected, including:

[0011] Based on the structure of the reactor to be tested, a two-dimensional axisymmetric electromagnetic field model is established using the finite element method;

[0012] Set material properties and electromagnetic field boundary conditions, determine the electrical parameters of the multi-segment coils, calculate the two-dimensional axisymmetric electromagnetic field model based on the electrical parameters, and obtain the magnetic field distribution and resistance matrix of the reactor to be tested;

[0013] According to the magnetic field distribution, the self-inductance of each coil and the mutual inductance between each coil and other coils are extracted, and the inductance matrix is ​​obtained based on the self-inductance and mutual inductance.

[0014] In a possible implementation of the first aspect, a three-dimensional electrostatic field model is constructed according to the coil winding structure in the reactor to be detected, and the three-dimensional electrostatic field model is solved to obtain a Maxwell capacitance matrix, including:

[0015] A three-dimensional electrostatic field model is constructed according to the coil winding structure in the reactor to be tested, wherein the control equation of the three-dimensional electrostatic field model is:

[0016]

[0017] n·D=0

[0018] Where D is the electric flux density, ρ v is the free charge volume density, E is the electric field strength, v is the electric potential, ε 0 is the vacuum dielectric constant, ε r is the relative dielectric constant, and n·D represents the electric flux in the normal direction of the boundary.

[0019] Set the electrostatic field material parameters and perform meshing, set the terminal boundary conditions and terminal type of the coil winding, take each coil as a steady-state source, and establish the terminal control equation;

[0020] Combined with the terminal control equations, the three-dimensional electrostatic field model is solved to obtain the Maxwell capacitance matrix.

[0021] In a possible implementation manner of the first aspect, a multi-conductor transmission line equivalent model is constructed according to a resistance matrix, an inductance matrix, and a Maxwell capacitance matrix, including:

[0022] The equivalent Berelon model is constructed based on the resistance matrix, inductance matrix and Maxwell capacitance matrix;

[0023] Based on the equivalent Berelon model, an equivalent model of multi-conductor transmission line is constructed.

[0024] In a possible implementation of the first aspect, an operating main frequency of a multi-conductor transmission line is determined based on an excitation signal, and an equivalent model of the multi-conductor transmission line is solved according to the operating main frequency to obtain reactance waves at different positions of a coil winding in a reactor to be detected, including:

[0025] The operating main frequency of the multi-conductor transmission line is determined based on the excitation signal, and the voltage difference and current difference at both ends of the multi-conductor transmission line at multiple locations are obtained as follows:

[0026]

[0027] In the formula, are the voltage difference and current difference at both ends of the multi-conductor transmission line, R i , L ij With C ij are the elements in the distributed resistance matrix R, the distributed inductance matrix L and the distributed capacitance matrix C;

[0028] The voltage difference and current difference at each position are differentiated respectively to obtain a voltage differential equation and a current differential equation, the voltage differential equation and the current differential equation are calculated respectively to obtain a voltage matrix and a current matrix, the voltage matrix and the current matrix are restored respectively to obtain a solution result, wherein the solution result includes the reactance waves at different positions of the coil winding in the inductor to be detected.

[0029] In a possible implementation manner of the first aspect, extracting features from each reactance wave to obtain a feature extraction result includes:

[0030] The reactance waves at different positions of the coil winding in the reactor to be tested are transformed using the Euler formula to obtain the voltage and current results at different positions.

[0031] The amplitude and harmonic content of the voltage and current results at different locations are extracted to obtain the feature extraction results.

[0032] A second aspect of an embodiment of the present invention provides a reactor fault diagnosis simulation device, comprising:

[0033] An acquisition module is used to acquire the recorded wave data of the reactor to be detected when it fails, and apply an excitation signal to the reactor according to the recorded wave data, wherein the excitation signal includes a DC component and an AC component;

[0034] A first calculation module is used to construct a two-dimensional axisymmetric electromagnetic field model based on the reactor structure of the reactor to be detected, and calculate the two-dimensional axisymmetric electromagnetic field model to obtain a resistance matrix and an inductance matrix of the reactor to be detected;

[0035] The first calculation module is used to construct a three-dimensional electrostatic field model according to the coil winding structure in the reactor to be detected, solve the three-dimensional electrostatic field model to obtain a Maxwell capacitance matrix, and construct a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix;

[0036] The fault judgment module is used to determine the main operating frequency based on the excitation signal, solve the multi-conductor transmission line equivalent model according to the main operating frequency, obtain the reactance waves at different positions of the coil winding in the inductor to be detected, extract the features in each reactance wave, obtain the feature quantity extraction result, compare the feature quantity with the ripple level under normal conditions, and obtain the fault diagnosis result of the inductor to be detected.

[0037] In a possible implementation manner of the second aspect, the first calculation module includes a construction unit, a simulation unit, and an inductance matrix calculation unit, wherein:

[0038] The construction unit is used to establish a two-dimensional axisymmetric electromagnetic field model based on the structure of the reactor to be detected and the finite element method;

[0039] The simulation unit is used to set material properties and electromagnetic field boundary conditions, and determine the electrical parameters of multiple coils. The two-dimensional axisymmetric electromagnetic field model is calculated based on the electrical parameters to obtain the magnetic field distribution and resistance matrix of the reactor to be tested.

[0040] The inductance matrix calculation unit is used to extract the self-inductance of each coil segment and the mutual inductance between each coil segment and other coils according to the magnetic field distribution, and obtain the inductance matrix based on the self-inductance and mutual inductance.

[0041] A third aspect of an embodiment of the present invention provides a computer device, including:

[0042] Memory for storing computer programs;

[0043] A processor is used to implement the reactor fault diagnosis simulation method of the first aspect when executing the computer program.

[0044] A fourth aspect of an embodiment of the present invention provides a storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the reactor fault diagnosis simulation method of the first aspect are implemented.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] The reactor fault diagnosis simulation method provided by the embodiment of the present invention obtains the recorded data of the reactor to be detected when it fails, and applies an excitation signal to the reactor according to the recorded data; constructs a two-dimensional axisymmetric electromagnetic field model based on the reactor structure of the reactor to be detected, calculates the two-dimensional axisymmetric electromagnetic field model, and obtains the resistance matrix and inductance matrix of the reactor to be detected; constructs a three-dimensional electrostatic field model according to the coil winding structure in the reactor to be detected, solves the three-dimensional electrostatic field model to obtain the Maxwell capacitance matrix, and constructs a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix; determines the operating main frequency based on the excitation signal, solves the multi-conductor transmission line equivalent model according to the operating main frequency, obtains the reactance waves at different positions of the coil winding in the reactor to be detected, extracts the features in each reactance wave, obtains the feature quantity extraction result, compares the feature quantity with the ripple level under normal conditions, and obtains the fault diagnosis result of the reactor to be detected. Through the above method, the reactor coil winding is equivalent to a multi-conductor transmission line for simulation calculation, thereby improving the accuracy of reactor fault diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A simulation method flow chart of an embodiment of a reactor fault diagnosis simulation method provided by the present invention;

[0048] Figure 2 A two-dimensional axisymmetric electromagnetic field model diagram of an embodiment of the reactor fault diagnosis simulation method provided by the present invention;

[0049] Figure 3 A three-dimensional electrostatic field model diagram of an embodiment of the reactor fault diagnosis simulation method provided by the present invention;

[0050] Figure 4 An equivalent Berelon model diagram of an embodiment of the reactor fault diagnosis simulation method provided by the present invention;

[0051] Figure 5 An equivalent model diagram of a multi-conductor transmission line of an embodiment of the reactor fault diagnosis simulation method provided by the present invention;

[0052] Figure 6 A device block diagram of another embodiment of the reactor fault diagnosis simulation method provided by the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0055] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0056] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0057] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0058] Therefore, a flowchart of an embodiment of a reactor fault diagnosis simulation method provided by an embodiment of the present invention is as follows: Figure 1 , including steps S101 to S104, each step is as follows:

[0059] S101, obtaining recorded wave data of a reactor to be detected when it fails, and applying an excitation signal to the reactor according to the recorded wave data, wherein the excitation signal includes a DC component and an AC component.

[0060] In this embodiment, a suitable AC / DC composite voltage excitation signal is selected according to the recording data when the reactor fails and the fault simulation needs. When simulating a reactor failure caused by a lightning impulse, a lightning impulse voltage should be selected. The expression of the lightning impulse voltage is:

[0061]

[0062] Where u(t) is the lightning impulse voltage, are all exponential decay terms, E 0 is the initial voltage amplitude.

[0063] Determine the appropriate lightning voltage amplitude, wave head time and half-peak time. When simulating the long-term impact of system high-order harmonics on the reactor, the AC / DC composite voltage excitation signal includes DC component and AC component, and the expression is:

[0064]

[0065] Where R(t) is the AC / DC composite voltage excitation signal, a 1 is the DC component, w is the angular frequency of the AC component, t is the time, The initial phase.

[0066] The above expression describes the relationship between the AC and DC composite voltage excitation signal and time in the simulation system. In practical applications, it is necessary to determine the frequency and corresponding amplitude of the excitation voltage according to the operating conditions of the reactor in order to more accurately simulate and analyze the performance of the reactor under lightning impulse and high-order harmonics.

[0067] S102: construct a two-dimensional axisymmetric electromagnetic field model based on the reactor structure of the reactor to be detected, calculate the two-dimensional axisymmetric electromagnetic field model, and obtain a resistance matrix and an inductance matrix of the reactor to be detected.

[0068] In this embodiment, according to the structure of the reactor, a two-dimensional axisymmetric model of the reactor is established based on the finite element method, material properties are set, electromagnetic field boundary conditions are set, and electrical parameters of multiple coils are determined according to the definition of mutual inductance; then, meshing is performed to analyze mesh convergence and mesh quality. The magnetic field distribution of the reactor is calculated, and finally, the self-inductance of each coil segment and the mutual inductance of the coil segment and other coil segments are extracted and combined into an inductance matrix.

[0069] In some embodiments, in step S102, "building a two-dimensional axisymmetric electromagnetic field model based on the reactor structure of the reactor to be detected, and calculating the two-dimensional axisymmetric electromagnetic field model to obtain a resistance matrix and an inductance matrix of the reactor to be detected" includes but is not limited to the following steps:

[0070] Based on the structure of the reactor to be tested, a two-dimensional axisymmetric electromagnetic field model is established using the finite element method;

[0071] Set material properties and electromagnetic field boundary conditions, determine the electrical parameters of the multi-segment coils, calculate the two-dimensional axisymmetric electromagnetic field model based on the electrical parameters, and obtain the magnetic field distribution and resistance matrix of the reactor to be tested;

[0072] According to the magnetic field distribution, the self-inductance of each coil and the mutual inductance between each coil and other coils are extracted, and the inductance matrix is ​​obtained based on the self-inductance and mutual inductance.

[0073] In this embodiment, the dry-type air-core reactor is mainly composed of an encapsulation, a support insulator, a star frame, a protective cover, and a stay. According to the design drawings of the reactor, the size and material parameters of the reactor such as the number of encapsulations, the number of encapsulation layers, the number of turns per layer, and the radius are extracted and reasonably simplified. The coil winding is the core part of the reactor, generally including a dummy encapsulation and a winding encapsulation, and the dummy encapsulation is generally located on the outside. The dummy encapsulation is separated from the adjacent winding encapsulation by glass fiber impregnated with epoxy resin, which plays the role of encapsulation insulation.

[0074] The main structures such as coil winding, encapsulated insulation and protective cover are constructed in the two-dimensional axisymmetric model, while the fasteners, pins and other parts that have little impact on the electromagnetic field simulation calculation are ignored. Taking the dry air-core reactor as an example for modeling, the electromagnetic field module of the multi-physics simulation software COMSOL Multiphysics is used to construct a simplified two-dimensional axisymmetric electromagnetic field model, such as Figure 2 As shown, the control equation in the electromagnetic field is established as:

[0075]

[0076] J=σE

[0077]

[0078] In the formula, H is the magnetic field intensity, J is the current intensity, B is the magnetic induction intensity, A is the vector magnetic potential, For the electric potential.

[0079] According to the reactor model, size and operating parameters, set the corresponding electromagnetic field material parameters, as shown in Table 1.

[0080] Table 1 Electromagnetic field material parameters of reactor

[0081]

[0082] In order to ensure accuracy and improve simulation efficiency, manual meshing is required. The meshing of air domain, reactor protection cover and encapsulation insulation is coarse, and the meshing of coil winding is fine. The meshing quality is checked after the meshing is completed. Set the coil boundary conditions in the electromagnetic field module, set the number of turns of each coil, add the rated current and voltage to each coil winding, and establish the coil control equation:

[0083]

[0084] Among them, J e is the coil current density, J e is the number of coil turns, V coil is the coil voltage, V ind is the induced voltage, A is the cross-sectional area of ​​the coil, Rcoil is the coil resistance, e coil is the coil direction unit vector.

[0085] Select the steady-state solver to perform coil geometry analysis, and then perform steady-state simulation based on the finite element method to solve the resistance matrix and inductance matrix of the reactor coil winding. The resistance matrix and inductance matrix can be written in the following form:

[0086]

[0087] In the formula, R 0 is the resistance matrix, R i is the resistance value, L 0 is the inductance matrix, L nn is the inductance.

[0088] Based on the electromagnetic field control equation and Joule loss theorem, a heat loss calculation model for the reactor is established, and the control equation is established:

[0089] P loss =∫∫∫J2σdv

[0090] Q=∫∫∫qdv

[0091] q=P loss

[0092] Among them, P loss is the power loss, Q is the heat generated, and q is the power density, which is loaded into the subsequently established temperature field model as an equivalent heat source for boundary condition setting.

[0093] S103, constructing a three-dimensional electrostatic field model according to the coil winding structure in the reactor to be detected, solving the three-dimensional electrostatic field model to obtain a Maxwell capacitance matrix, and constructing a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix.

[0094] In this embodiment, since there is no coil boundary condition in the electrostatic field module of the two-dimensional axisymmetric model, when using the electrostatic field module to calculate the Maxwell capacitance, it is necessary to use a three-dimensional model to model the coil winding, solve the three-dimensional electrostatic field model, obtain the Maxwell capacitance matrix, and construct a multi-conductor transmission line equivalent model based on the resistance matrix, inductance matrix and Maxwell capacitance matrix.

[0095] In some embodiments, in step S103, "building a three-dimensional electrostatic field model according to the coil winding structure in the reactor to be detected, solving the three-dimensional electrostatic field model to obtain a Maxwell capacitance matrix" includes but is not limited to the following steps:

[0096] A three-dimensional electrostatic field model is constructed according to the coil winding structure in the reactor to be tested, wherein the control equation of the three-dimensional electrostatic field model is:

[0097]

[0098] n·D=0

[0099] Where D is the electric flux density, ρv is the free charge volume density, E is the electric field strength, v is the electric potential, and ε 0 is the vacuum dielectric constant, ε r is the relative dielectric constant, and n·D represents the electric flux in the normal direction of the boundary.

[0100] Set the electrostatic field material parameters and perform meshing, set the terminal boundary conditions and terminal type of the coil winding, take each coil as a steady-state source, and establish the terminal control equation;

[0101] Combined with the terminal control equations, the three-dimensional electrostatic field model is solved to obtain the Maxwell capacitance matrix.

[0102] In this embodiment, the main structures such as coil windings, encapsulated insulation and protective covers are considered, and the fasteners, pins and other parts that have little influence on the electromagnetic field simulation calculation are ignored. The multi-physics field simulation software COMSOL The electrostatic field module of the dry-type air-core reactor is used to perform three-dimensional electrostatic field modeling. Figure 3 As shown, the electrostatic field control equation is established:

[0103]

[0104] n·D=0

[0105] Where D is the electric flux density, ρ v is the free charge volume density, E is the electric field strength, v is the electric potential, ε 0 is the vacuum dielectric constant, ε r is the relative dielectric constant, and n·D represents the electric flux in the normal direction of the boundary.

[0106] According to the reactor model, size and operating parameters, the size parameters such as the radius, number of turns, pitch and rotation direction of the coil winding are set in the geometry module of the 3D model, and then the corresponding electrostatic field material parameters are set for the geometric entities of different parts of the reactor, as shown in Table 2.

[0107] Table 2 Electrostatic field material parameters of reactor

[0108]

[0109] Manually mesh the geometric entity area, where the air domain, reactor protection cover and encapsulation insulation are meshed coarsely, and the coil winding part is meshed finely. After the meshing is completed, check the meshing quality. Then set the terminal boundary conditions and terminal type for the coil winding in the electrostatic field module, treat each coil as a steady-state source, and establish the terminal control equation:

[0110]

[0111] Where D is the electric flux density, Represents the boundary of the closed surface Ω.

[0112] Select the steady-state solver, perform steady-state source scanning, and solve the Maxwell capacitance matrix of the reactor coil winding. The Maxwell capacitance matrix can also be written in the following form:

[0113]

[0114] In the formula, C 0 is the Maxwell capacitance matrix, C nn is the Maxwell capacitance value.

[0115] In some embodiments, in step S103, “constructing a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix” includes but is not limited to the following steps:

[0116] The equivalent Berelon model is constructed based on the resistance matrix, inductance matrix and Maxwell capacitance matrix;

[0117] Based on the equivalent Berelon model, an equivalent model of multi-conductor transmission line is constructed.

[0118] In this embodiment, there is electromagnetic coupling between different positions of the coil winding of the reactor, mutual inductance and inter-turn capacitance exist between different turns of the coil, inter-layer capacitance exists between different layers, and there is stray capacitance between the coil winding and the ground. The equivalent Berelon model of the coil winding contains resistance, self-inductance, mutual inductance, inter-turn capacitance, inter-layer capacitance and stray capacitance. The circuit element parameters in the Berelon model are obtained through the finite element simulation calculation of the first and second steps. The equivalent Berelon model of the reactor coil winding as described above is as follows: Figure 4 shown.

[0119] The equivalent Berelon model of the reactor coil winding can reflect the electromagnetic coupling phenomenon between different turns and different layers of the coil winding, but it cannot reflect the reflection and transmission process of electromagnetic waves propagating in the coil winding. Therefore, according to the equivalent Berelon circuit model of the coil winding, a multi-conductor transmission line equivalent model based on the Berelon model of the coil winding is constructed, such as Figure 5As shown in Figure 2, the number of phases and length of the multi-conductor transmission line are determined based on the electromagnetic field and three-dimensional electrostatic field model of the reactor.

[0120] S104. Determine the main operating frequency based on the excitation signal, solve the multi-conductor transmission line equivalent model according to the main operating frequency, obtain the reactance waves at different positions of the coil winding in the inductor to be tested, extract the features in each reactance wave to obtain the feature extraction result, compare the feature with the ripple level under normal conditions, and obtain the fault diagnosis result of the inductor to be tested.

[0121] In this embodiment, the AC / DC composite voltage excitation signal determines the operating main frequency f of the multi-conductor transmission line. The selected AC / DC composite excitation signal is used as the system excitation voltage to perform wave process simulation on the multi-conductor transmission line, pre-process the waveform data of the voltage and current of the multi-conductor transmission line changing with time, extract the characteristic quantities such as the amplitude and harmonic content of the reactor coil winding wave process, and compare them with the characteristic quantities of the normal operating condition of the reactor to determine the fault condition of the reactor coil winding.

[0122] In some embodiments, in step S104, "determining the operating main frequency of the multi-conductor transmission line based on the excitation signal, solving the equivalent model of the multi-conductor transmission line according to the operating main frequency, and obtaining the reactance waves at different positions of the coil winding in the reactor to be detected" includes but is not limited to the following steps:

[0123] The operating main frequency of the multi-conductor transmission line is determined based on the excitation signal, and the voltage difference and current difference at both ends of the multi-conductor transmission line at multiple locations are obtained as follows:

[0124]

[0125]

[0126] In the formula, are the voltage difference and current difference at both ends of the multi-conductor transmission line, R i , L ij With C ij are the elements in the distributed resistance matrix R, the distributed inductance matrix L and the distributed capacitance matrix C;

[0127] The voltage difference and current difference at each position are differentiated respectively to obtain a voltage differential equation and a current differential equation, the voltage differential equation and the current differential equation are calculated respectively to obtain a voltage matrix and a current matrix, the voltage matrix and the current matrix are restored respectively to obtain a solution result, wherein the solution result includes the reactance waves at different positions of the coil winding in the inductor to be detected.

[0128] In this embodiment, in the equivalent Berelon model of the coil winding, the voltage difference and current difference at both ends of the wire of length dz can be derived using Kirchhoff's voltage law and Kirchhoff's current law:

[0129]

[0130] Also written in matrix form:

[0131]

[0132] Among them, R i , L ij With C ij It is an element in the distributed resistance matrix R, distributed inductance matrix L and distributed capacitance matrix C.

[0133] The distributed resistance matrix R, distributed inductance matrix L and distributed capacitance matrix C are derived from the finite element simulation results of the two-dimensional axisymmetric electromagnetic field model and the three-dimensional electrostatic field model, and the expressions are as follows:

[0134]

[0135]

[0136] Where R is the distributed resistance matrix, L is the distributed inductance matrix, and C is the distributed capacitance matrix.

[0137] The Z matrix and the Y matrix are derived from the distributed resistance matrix R, the distributed inductance matrix L and the distributed capacitance matrix C. By differentiating the voltage and current differential equations again, we can get the second-order differential equations for voltage and current decoupling:

[0138]

[0139] Taking the voltage second-order differential equation system as an example, let:

[0140] A=ZY

[0141] Expanding the constant term yields:

[0142]

[0143] Among them, a ij (1≤i≤n,1≤j≤n) is an element in the A matrix.

[0144] Since the off-diagonal elements of the A matrix in the voltage second-order differential equation system are non-zero elements, it is necessary to perform similar diagonal processing on the A matrix:

[0145]

[0146] Among them, T Uis the similarity transformation matrix, Λ U is a diagonal matrix similar to A.

[0147] Then transform the voltage phasor and let:

[0148]

[0149] Then the second-order differential equation of voltage is transformed into:

[0150]

[0151] The writing matrix form is:

[0152]

[0153] Solving the second-order differential equation yields:

[0154]

[0155] Restore the voltage matrix to the true solution:

[0156]

[0157] In the formula, and is the complex amplitude of the incident voltage wave and the reflected voltage wave in different propagation modes of the multi-conductor transmission line.

[0158] The real solution of the current wave equation of multi-conductor transmission lines is solved according to the second-order differential equation of current:

[0159]

[0160] in, and is the complex amplitude of the incident current wave and the reflected current wave in different propagation modes of the multi-conductor transmission line.

[0161] In some embodiments, step S104 of "extracting features from each of the reactance waves to obtain feature extraction results" includes but is not limited to the following steps:

[0162] The reactance waves at different positions of the coil winding in the reactor to be tested are transformed using the Euler formula to obtain the voltage and current results at different positions.

[0163] The amplitude and harmonic content of the voltage and current results at different locations are extracted to obtain the feature extraction results.

[0164] In this embodiment, for different positions 0≤z on the multi-conductor transmission line 0≤l, according to the differential equation of voltage and current of multi-conductor transmission line, the wave process of voltage and current at different positions of reactor coil winding can be obtained:

[0165]

[0166] Let a′ ii =α i +jβ i , b′ ii =α′ i +jβ′ i , using Euler's formula to transform the wave process of voltage and current, we can get the voltage and current of multi-conductor transmission line in the form of sinusoidal function:

[0167]

[0168] In the formula, The positions z 0 The complex amplitudes of the incident and reflected voltage waves of different propagation modes of the multi-conductor transmission line at and is the complex amplitude of the incident current wave and the reflected current wave in different propagation modes of the multi-conductor transmission line.

[0169] According to the voltage and current results at different positions, characteristic quantities such as amplitude and harmonic content are taken and compared with the rated operating current and ripple level of the reactor to determine the fault condition of the reactor coil winding.

[0170] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0171] In some embodiments, Figure 6 As shown, it shows a block diagram of a reactor fault diagnosis simulation device 600 provided in an embodiment of the present application, including: an acquisition module 601, a first calculation module 602, a second calculation module 603 and a fault judgment module 604, wherein:

[0172] An acquisition module, used for acquiring the recorded wave data of the reactor to be detected when it fails, and applying an excitation signal to the reactor according to the recorded wave data, wherein the excitation signal includes a DC component and an AC component;

[0173] A first calculation module is used to construct a two-dimensional axisymmetric electromagnetic field model based on the reactor structure of the reactor to be detected, and calculate the two-dimensional axisymmetric electromagnetic field model to obtain a resistance matrix and an inductance matrix of the reactor to be detected;

[0174] A second calculation module is used to construct a three-dimensional electrostatic field model according to the coil winding structure in the reactor to be detected, solve the three-dimensional electrostatic field model to obtain a Maxwell capacitance matrix, and construct a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix;

[0175] A fault judgment module is used to determine the main operating frequency based on the excitation signal, solve the multi-conductor transmission line equivalent model according to the main operating frequency, obtain the reactance waves at different positions of the coil winding in the inductor to be detected, extract the features in each of the reactance waves to obtain a feature quantity extraction result, compare the feature quantity with the ripple level under normal conditions, and obtain a fault diagnosis result of the inductor to be detected.

[0176] In some embodiments, the first calculation module includes a construction unit, a simulation unit and an inductance matrix calculation unit, wherein:

[0177] The construction unit is used to establish a two-dimensional axisymmetric electromagnetic field model based on the structure of the reactor to be detected and the finite element method;

[0178] The simulation unit is used to set material properties and electromagnetic field boundary conditions, and determine the electrical parameters of multiple coils. The two-dimensional axisymmetric electromagnetic field model is calculated based on the electrical parameters to obtain the magnetic field distribution and resistance matrix of the reactor to be tested.

[0179] The inductance matrix calculation unit is used to extract the self-inductance of each coil segment and the mutual inductance between each coil segment and other coils according to the magnetic field distribution, and obtain the inductance matrix based on the self-inductance and mutual inductance.

[0180] The specific implementation of the reactor fault diagnosis simulation device is basically the same as the specific implementation of the reactor fault diagnosis simulation method described above, and will not be repeated here.

[0181] In one embodiment of the present application, a computer device is provided, which includes a memory and a processor, wherein a computer program is stored in the memory, and the above steps are implemented when the processor executes the computer program; the computer device provided in this embodiment has an implementation principle and technical effects similar to those of the above method embodiments, and will not be repeated here.

[0182] In one embodiment of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and the above steps are implemented when the computer program is executed by a processor; the computer-readable storage medium provided in this embodiment has an implementation principle and technical effects similar to those of the above method embodiment, and will not be repeated here.

[0183] 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.

[0184] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A reactor fault diagnosis simulation method, characterized in that: include: Acquire recorded wave data of the reactor to be detected when it fails, and apply an excitation signal to the reactor according to the recorded wave data, wherein the excitation signal includes a DC component and an AC component; A two-dimensional axisymmetric electromagnetic field model is constructed based on the reactor structure of the reactor to be detected, and the two-dimensional axisymmetric electromagnetic field model is calculated to obtain a resistance matrix and an inductance matrix of the reactor to be detected; A three-dimensional electrostatic field model is constructed according to the coil winding structure in the reactor to be detected, the three-dimensional electrostatic field model is solved to obtain a Maxwell capacitance matrix, and a multi-conductor transmission line equivalent model is constructed according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix; The operating main frequency is determined based on the excitation signal, and the multi-conductor transmission line equivalent model is solved according to the operating main frequency to obtain the reactance waves at different positions of the coil winding in the inductor to be detected, and the features in each of the reactance waves are extracted to obtain a feature quantity extraction result, and the feature quantity is compared with the ripple level under normal conditions to obtain a fault diagnosis result of the inductor to be detected.

2. The reactor fault diagnosis simulation method according to claim 1, characterized in that: The two-dimensional axisymmetric electromagnetic field model is constructed based on the reactor structure of the reactor to be detected, and the two-dimensional axisymmetric electromagnetic field model is calculated to obtain the resistance matrix and the inductance matrix of the reactor to be detected, including: Based on the structure of the reactor to be detected, the two-dimensional axisymmetric electromagnetic field model is established based on the finite element method; Setting material properties and electromagnetic field boundary conditions, and determining electrical parameters of the multi-segment coils, calculating the two-dimensional axisymmetric electromagnetic field model according to the electrical parameters, and obtaining the magnetic field distribution and resistance matrix of the reactor to be detected; According to the magnetic field distribution, the self-inductance of each coil segment and the mutual inductance between each coil segment and other coils are extracted, and an inductance matrix is ​​obtained based on the self-inductance and the mutual inductance.

3. The reactor fault diagnosis simulation method according to claim 2, characterized in that: The three-dimensional electrostatic field model is constructed according to the coil winding structure in the reactor to be detected, and the three-dimensional electrostatic field model is solved to obtain the Maxwell capacitance matrix, including: A three-dimensional electrostatic field model is constructed according to the coil winding structure in the reactor to be detected, wherein the control equation of the three-dimensional electrostatic field model is: n·D=0 Where D is the electric flux density, ρ v is the free charge volume density, E is the electric field strength, v is the electric potential, ε0 is the vacuum dielectric constant, ε r is the relative dielectric constant, n·D represents the electric flux in the normal direction of the boundary; Set the electrostatic field material parameters and perform meshing, set the terminal boundary conditions and terminal type of the coil winding, take each coil as a steady-state source, and establish the terminal control equation; In combination with the terminal control equation, the three-dimensional electrostatic field model is solved to obtain the Maxwell capacitance matrix.

4. The reactor fault diagnosis simulation method according to claim 1, characterized in that: The constructing of a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix comprises: An equivalent Berelon model is constructed according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix; Based on the equivalent Berelon model, an equivalent model of a multi-conductor transmission line is constructed.

5. The reactor fault diagnosis simulation method according to claim 1, characterized in that: The method of determining the operating main frequency of the multi-conductor transmission line based on the excitation signal, solving the equivalent model of the multi-conductor transmission line according to the operating main frequency, and obtaining the reactance waves at different positions of the coil winding in the reactor to be detected includes: The operating main frequency of the multi-conductor transmission line is determined based on the excitation signal, and the voltage difference and current difference at both ends of the multi-conductor transmission line at multiple positions are obtained as follows: In the formula, are the voltage difference and current difference at both ends of the multi-conductor transmission line, R i , L ij With C ij are the elements in the distributed resistance matrix R, the distributed inductance matrix L and the distributed capacitance matrix C; The voltage difference and the current difference at each position are differentiated respectively to obtain a voltage differential equation and a current differential equation, the voltage differential equation and the current differential equation are calculated respectively to obtain a voltage matrix and a current matrix, the voltage matrix and the current matrix are restored respectively to obtain a solution result, wherein the solution result includes the reactance waves at different positions of the coil winding in the inductor to be detected.

6. The reactor fault diagnosis simulation method according to claim 1, characterized in that: The extracting of the features from each of the reactance waves to obtain a feature extraction result includes: The reactance waves at different positions of the coil winding in the reactor to be tested are transformed by using the Euler formula to obtain voltage results and current results at different positions; The amplitude and harmonic content in the voltage results and current results at the different positions are extracted to obtain a feature extraction result.

7. A reactor fault diagnosis simulation device, characterized in that: include: An acquisition module, used for acquiring the recorded wave data of the reactor to be detected when it fails, and applying an excitation signal to the reactor according to the recorded wave data, wherein the excitation signal includes a DC component and an AC component; A first calculation module is used to construct a two-dimensional axisymmetric electromagnetic field model based on the reactor structure of the reactor to be detected, and calculate the two-dimensional axisymmetric electromagnetic field model to obtain a resistance matrix and an inductance matrix of the reactor to be detected; A second calculation module is used to construct a three-dimensional electrostatic field model according to the coil winding structure in the reactor to be detected, solve the three-dimensional electrostatic field model to obtain a Maxwell capacitance matrix, and construct a multi-conductor transmission line equivalent model according to the resistance matrix, the inductance matrix and the Maxwell capacitance matrix; A fault judgment module is used to determine the main operating frequency based on the excitation signal, solve the multi-conductor transmission line equivalent model according to the main operating frequency, obtain the reactance waves at different positions of the coil winding in the inductor to be detected, extract the features in each of the reactance waves to obtain a feature quantity extraction result, compare the feature quantity with the ripple level under normal conditions, and obtain a fault diagnosis result of the inductor to be detected.

8. The reactor fault diagnosis simulation device according to claim 7, characterized in that: The first calculation module includes a construction unit, a simulation unit and an inductance matrix calculation unit, wherein: The construction unit is used to establish the two-dimensional axisymmetric electromagnetic field model based on the structure of the reactor to be detected and based on the finite element method; The simulation unit is used to set material properties and electromagnetic field boundary conditions, and determine electrical parameters of the multi-segment coils, and calculate the two-dimensional axisymmetric electromagnetic field model according to the electrical parameters to obtain the magnetic field distribution and resistance matrix of the reactor to be detected; The inductance matrix calculation unit is used to extract the self-inductance of each coil segment and the mutual inductance between each coil segment and other coils according to the magnetic field distribution, and obtain the inductance matrix based on the self-inductance and the mutual inductance.

9. A computer device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the reactor fault diagnosis simulation method as claimed in any one of claims 1 to 6 when executing the computer program.

10. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the reactor fault diagnosis simulation method according to any one of claims 1 to 6 is implemented.

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