A transformer current signal simulation method, device and medium for circuit model

Abstract

The embodiments of this specification disclose a transformer current signal simulation method, device and medium for a circuit model, which relate to the technical field of transformers. The method includes: determining actual parameters of a transformer corresponding to a transformer to be simulated, and simulating a multi-order oscillation process of a steep wave signal based on the actual parameters of the transformer to construct a high-frequency correction unit; correcting a pre-constructed double-pie equivalent circuit unit corresponding to the transformer to be simulated through the high-frequency correction unit to generate a double-pie unit high-frequency equivalent circuit model; determining a pre-constructed specified equivalent circuit model corresponding to the transformer to be simulated, and constructing a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated based on the double-pie unit high-frequency equivalent circuit model, a pre-set fourth transverse capacitor and the specified equivalent circuit model, so as to simulate the signal propagation of the local discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model.

Description

Technical Field

[0001] This specification relates to the field of transformer technology, and in particular to a transformer current signal simulation method, device, and medium for a circuit model. Background Art

[0002] The high-frequency current method is currently a widely used method for detecting partial discharge (PD) in transformers. By detecting the pulsed current signals generated by PD, it can promptly detect insulation defects, which is crucial for ensuring the safe and stable operation of transformers. Equivalent circuit models are an effective tool for studying the transient response of transformer windings to broadband PD signals. By establishing an equivalent circuit model of the transformer winding, the propagation of PD signals can be simulated, and the signal's propagation path and attenuation patterns can be analyzed, thus guiding broadband PD detection.

[0003] When building equivalent circuit models, turns or pancakes are generally used as the basic units. The premise for equivalent lumped parameters is that the total length of the conductor is significantly less than the wavelength of the signal. Therefore, traditional models are generally only applicable to frequency ranges below 1MHz and cannot simulate the propagation of high-frequency signals measured by broadband detection technology. In addition, in actual engineering, only a few transformer bushings have the conditions to measure pulse current using the down conductor method or burying sensors in the bushing end screen grounding device. More often, the signal is measured at the core grounding point. In addition to the core leg with the coil wound around it, the transformer core also has a yoke. However, when building equivalent circuit models, existing models only consider the capacitance between the core leg and the low-voltage winding, and do not consider the capacitance between the high-voltage winding and the core yoke. Therefore, existing models cannot truly reflect the attenuation law of the signal propagating to the core.

[0004] Therefore, when simulating transformer current signals, the traditional equivalent circuit model is only applicable to the frequency range below 1 MHz, and does not take into account the capacitance between the high-voltage winding and the core side yoke. As a result, the simulation results cannot meet the signal propagation law, and the simulation effect needs to be improved. Summary of the Invention

[0005] One or more embodiments of this specification provide a transformer current signal simulation method, device and medium based on a circuit model, which are used to solve the following technical problems: when simulating transformer current signals, the traditional equivalent circuit model is only applicable to the frequency range below 1 MHz, and does not take into account the capacitance between the high-voltage winding and the core side yoke, resulting in the simulation results being unable to meet the signal propagation law, and the simulation effect needs to be improved.

[0006] One or more embodiments of this specification adopt the following technical solutions:

[0007] One or more embodiments of the present specification provide a transformer current signal simulation method for a circuit model, the method comprising: determining actual transformer parameters corresponding to a transformer to be simulated, simulating a multi-order oscillation process of a steep wave signal based on the actual transformer parameters to construct a high-frequency correction unit; correcting a pre-constructed two-wire equivalent circuit unit corresponding to the transformer to be simulated through the high-frequency correction unit to generate a two-wire unit high-frequency equivalent circuit model; determining a pre-constructed specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes a two-wire equivalent circuit unit, a first transverse capacitance between the core and the low-voltage winding, a second transverse capacitance between the low-voltage winding and the high-voltage winding, and a third transverse capacitance between the high-voltage winding and the casing; constructing a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated based on the two-wire unit high-frequency equivalent circuit model, a pre-set fourth transverse capacitance, and the specified equivalent circuit model, so as to simulate the signal propagation of the partial discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model.

[0008] Furthermore, based on the actual parameters of the transformer, the multi-order oscillation process of the steep wave signal is simulated to construct a high-frequency correction unit, specifically including: constructing an LC parallel resonance unit to simulate the multi-order oscillation process of the steep wave signal to determine the circuit parameters of each of the LC parallel resonance units corresponding to the multi-order oscillation according to the actual parameters of the transformer, wherein the circuit parameters include the capacitance and inductance of the LC parallel resonance unit; according to the circuit parameters of each of the LC parallel resonance units corresponding to the multi-order oscillation, multiple LC parallel resonance units are connected in series to determine a multi-order LC parallel resonance circuit corresponding to the multi-order oscillation process; and a specified parallel resistor is introduced into each of the LC parallel resonance units in the multi-order LC parallel resonance circuit to construct the high-frequency correction unit.

[0009] Furthermore, according to the actual parameters of the transformer, the circuit parameters of each of the LC parallel resonance units corresponding to the multi-order oscillation are determined, specifically including: simulating the fundamental oscillation frequency caused by reflection during the steep wave propagation process according to the actual parameters of the transformer by a first preset formula, and determining the first circuit parameters of the first LC parallel resonance unit corresponding to the fundamental oscillation; the first preset formula includes and Wherein, C' is the capacitance of the first LC parallel resonant unit, L' is the inductance of the first LC parallel resonant unit, ε0 represents the dielectric constant of vacuum, ε P represents the relative dielectric constant of the conductor, μ0 represents the magnetic permeability of vacuum, d a Indicates the average diameter of the conductor, h d Indicates the height of the conductor, a Prepresents the thickness of the turn insulation, and n is the number of turns of the transformer to be simulated; based on the fundamental oscillation frequency, a high-order resonant frequency corresponding to an integer multiple of the fundamental oscillation frequency is determined, so as to determine the high-order circuit parameters of the high-order LC parallel resonant unit corresponding to the high-order resonant frequency through a second preset formula and the first circuit parameters of the first LC parallel resonant unit; the second preset formula is: Among them, L′ m is the inductance of the m-order LC parallel resonant unit, C′ m is the capacitance of the m-order LC parallel resonant unit.

[0010] Furthermore, the specified parallel resistance is Where R′ is the specified parallel resistance, ε0 is the dielectric constant of vacuum, and ε P represents the relative dielectric constant of the conductor, μ0 represents the magnetic permeability of vacuum, d a Indicates the average diameter of the conductor, h d Indicates the height of the conductor, a P It represents the thickness of the turn insulation, σ is the correction factor, and n is the number of turns of the transformer coil to be simulated.

[0011] Furthermore, the high-frequency correction unit is used to correct a pre-constructed two-wire equivalent circuit unit corresponding to the transformer to be simulated to generate a high-frequency equivalent circuit model of the two-wire unit. This method specifically includes: obtaining a two-wire equivalent circuit unit corresponding to the transformer to be simulated, wherein the two-wire equivalent circuit unit includes the resistance, self-inductance and equivalent capacitance of the two-wire unit; and connecting the high-frequency correction unit and the equivalent capacitance in series in the two-wire equivalent circuit unit to generate a high-frequency equivalent circuit model of the two-wire unit.

[0012] Furthermore, based on the high-frequency equivalent circuit model of the two-wire cake unit, the preset fourth transverse capacitor and the specified equivalent circuit model, a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated is constructed, specifically including: determining the specified equivalent circuit model, wherein the specified equivalent circuit model includes a low-voltage winding unit and a high-voltage winding unit, the low-voltage winding unit includes a plurality of first two-wire cake equivalent circuit units, and the high-voltage winding unit includes a plurality of second two-wire cake equivalent circuit units; using the high-frequency equivalent circuit model of the two-wire cake unit, the plurality of second two-wire cake equivalent circuit units are replaced, and the fourth transverse capacitor is added to construct the core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated.

[0013] Furthermore, adding a fourth transverse capacitor specifically includes: adding the fourth transverse capacitor between the high-voltage winding and the core grounding point of the specified equivalent circuit model, wherein the fourth transverse capacitor is the transverse capacitor between the high-voltage winding and the core side yoke.

[0014] Furthermore, the signal propagation of the local discharge high-frequency current generated by the transformer to be simulated is simulated through the core-winding high-frequency equivalent circuit model, specifically including: determining multiple component parameters of the core-winding high-frequency equivalent circuit model through the actual transformer parameters of the transformer to be simulated; based on the multiple component parameters, injecting a pulse signal at a specified position of the core-winding high-frequency equivalent circuit model to simulate the local discharge process, so as to determine the signal propagation simulation data of the high-frequency current.

[0015] One or more embodiments of this specification provide a transformer current signal simulation device for a circuit model, including:

[0016] at least one processor; and,

[0017] a memory communicatively connected to the at least one processor; wherein,

[0018] The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

[0019] Determine the actual parameters of the transformer corresponding to the transformer to be simulated, and based on the actual parameters of the transformer, simulate the multi-order oscillation process of the steep wave signal to construct a high-frequency correction unit; correct the pre-constructed double-pie equivalent circuit unit corresponding to the transformer to be simulated through the high-frequency correction unit to generate a high-frequency equivalent circuit model of the double-pie unit; determine the pre-constructed specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes the double-pie equivalent circuit unit, the first transverse capacitance between the iron core and the low-voltage winding, the second transverse capacitance between the low-voltage winding and the high-voltage winding, and the third transverse capacitance between the high-voltage winding and the casing; construct the core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated according to the double-pie high-frequency equivalent circuit model, the pre-set fourth transverse capacitance and the specified equivalent circuit model, so as to simulate the signal propagation of the local discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model.

[0020] One or more embodiments of this specification provide a non-volatile computer storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to:

[0021] Determine the actual parameters of the transformer corresponding to the transformer to be simulated, and based on the actual parameters of the transformer, simulate the multi-order oscillation process of the steep wave signal to construct a high-frequency correction unit; correct the pre-constructed double-pie equivalent circuit unit corresponding to the transformer to be simulated through the high-frequency correction unit to generate a high-frequency equivalent circuit model of the double-pie unit; determine the pre-constructed specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes the double-pie equivalent circuit unit, the first transverse capacitance between the iron core and the low-voltage winding, the second transverse capacitance between the low-voltage winding and the high-voltage winding, and the third transverse capacitance between the high-voltage winding and the casing; construct the core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated according to the double-pie high-frequency equivalent circuit model, the pre-set fourth transverse capacitance and the specified equivalent circuit model, so as to simulate the signal propagation of the local discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model.

[0022] At least one of the above-mentioned technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects: through the above-mentioned technical solution, based on the wave process of high-frequency signal propagation, a high-frequency correction unit of the double-pie cake equivalent circuit is established, and the double-pie cake unit of the tangled winding is corrected. The wave process of the signal propagating in the winding is taken into account, and the fundamental frequency oscillation, second-order and third-order oscillation of the high-frequency signal propagating in the winding are simulated, which significantly improves the frequency upper limit of the model and can accurately simulate the impedance characteristics of the winding within a frequency range of up to 10MHz; the lateral capacitance between the high-voltage winding and the core side yoke is taken into account, and the equivalent circuit of the double-pie cake unit of the tangled winding on the high-voltage side is corrected, and the ground capacitance branch of the high-voltage winding is improved, so that the current signal at the core grounding point can be accurately simulated, which is more in line with actual partial discharge detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some of the embodiments described in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work. In the drawings:

[0024] Figure 1 A schematic flow chart of a transformer current signal simulation method for a circuit model provided in an embodiment of this specification;

[0025] Figure 2 A schematic diagram of the circuit structure of a high-frequency correction unit provided in an embodiment of this specification;

[0026] Figure 3A schematic diagram of the circuit structure of a traditional two-wire pancake equivalent circuit unit provided in an embodiment of this specification;

[0027] Figure 4 A schematic diagram of the circuit structure of a high-frequency equivalent circuit model of a two-wire pancake unit provided in an embodiment of this specification;

[0028] Figure 5 A schematic diagram of the circuit structure of a core-winding high-frequency equivalent circuit model provided in an embodiment of this specification;

[0029] Figure 6 A schematic diagram of simulation and measurement results of an impedance spectrum of a high-voltage winding provided in an embodiment of the specification;

[0030] Figure 7 A schematic diagram of simulation results and test results of a high-frequency current signal at a core grounding point provided in an embodiment of this specification;

[0031] Figure 8 A schematic diagram of the structure of a transformer current signal simulation device of a circuit model provided in an embodiment of this specification. DETAILED DESCRIPTION

[0032] To help those skilled in the art better understand the technical solutions in this specification, the following will provide a clear and complete description of the technical solutions in the embodiments of this specification, in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this specification without creative work should fall within the scope of protection of this specification.

[0033] The high-frequency current method is currently a widely used method for transformer partial discharge detection. By detecting the pulse current signals generated by partial discharge, it can promptly detect insulation defects, which is of great significance for ensuring the safe and stable operation of transformers. Traditional pulse current detection has a low frequency band and limited bandwidth, which cannot fully capture discharge information. With the development of broadband partial discharge detection technology, this technology, with its high bandwidth and strong anti-interference capabilities, has become a new trend in partial discharge detection. However, because windings attenuate signals of different frequencies to varying degrees, the complex propagation paths and attenuation patterns of high-frequency signals pose challenges to broadband partial discharge detection. With the emergence and development of digital twin technology for power equipment, accurate physical simulation based on simulation models has received increasing attention. Equivalent circuit models are an effective means of studying the transient response of transformer windings to broadband partial discharge signals. By establishing an equivalent circuit model of the transformer winding, the propagation process of the partial discharge signal can be simulated, the signal propagation path and attenuation characteristics can be analyzed, and thus guiding broadband partial discharge detection. Therefore, an accurate equivalent circuit model is crucial for analyzing the propagation characteristics of partial discharge signals and improving the accuracy of broadband partial discharge detection.

[0034] Equivalent circuit models are typically built using turns or pancakes as the basic unit. The assumption for equivalent lumped parameters is that the total length of the conductor is significantly less than the signal's wavelength. Therefore, traditional models are generally only applicable to frequencies below 1 MHz and cannot simulate the propagation of high-frequency signals measured by broadband detection techniques. Furthermore, in actual projects, only a few transformer bushings have the conditions for measuring pulse currents using downconductors or embedding sensors in the bushing end shield grounding system. More often, signals are measured at the core ground. In addition to the core leg with the coils wound around it, the transformer core also has a yoke. However, existing equivalent circuit models only consider the capacitance between the core leg and the low-voltage winding, not the capacitance between the high-voltage winding and the core yoke. Therefore, these models cannot accurately reflect the attenuation of signals propagating into the core. Therefore, improving the accuracy of equivalent circuit models at high frequencies while accurately simulating the high-frequency current signals at the core ground is a challenge in accurately simulating partial discharge signal propagation.

[0035] Existing equivalent circuit models generally divide transformer windings into several basic units based on their winding configuration. Each unit consists of components such as longitudinal capacitance, transverse capacitance, resistors, and inductors, while also accounting for the mutual inductance between different units. To address the low upper frequency limit of equivalent circuit models, the primary approach currently employed is to improve the accuracy of circuit parameter calculations, for example, by utilizing finite element simulation software. Another common approach is to consider stray winding parameters, such as introducing stray capacitance to improve the circuit model. However, these modeling methods often fail to account for the wave process of high-frequency signal propagation in the windings, resulting in limited improvement in the upper frequency limit of the equivalent circuit model. Furthermore, these models also fail to account for the transverse capacitance between the high-voltage winding and the core yoke, limiting their application. In summary, further research is needed to develop equivalent circuit models that are applicable to high frequencies and can accurately simulate core grounding signals.

[0036] The embodiments of this specification provide a transformer current signal simulation method for a circuit model. It should be noted that the execution subject in the embodiments of this specification can be a server or any device with data processing capabilities. Figure 1 A schematic diagram of a flow chart of a transformer current signal simulation method for a circuit model provided in an embodiment of this specification, such as Figure 1 As shown, it mainly includes the following steps:

[0037] Step S101 : determining actual transformer parameters corresponding to the transformer to be simulated, and simulating a multi-order oscillation process of a steep wave signal based on the actual transformer parameters to construct a high-frequency correction unit.

[0038] In one embodiment of this specification, when studying the propagation of partial discharge signals within a winding, the signal's wave process cannot be ignored due to its high frequency. Steep waves reflect at the junction of the coils and oscillate with a period corresponding to the time it takes to propagate back and forth within the coil. An LC parallel resonant circuit is constructed to simulate this process. While considering the fundamental oscillation frequency caused by reflection during the steep wave propagation process, higher-order resonant frequencies that are integer multiples of the fundamental oscillation frequency are further considered, along with the signal's second- and third-order oscillation processes. Simulation is also performed using the LC parallel resonant circuit. The actual transformer parameters corresponding to the transformer to be simulated are determined. Based on these actual transformer parameters, the multi-order oscillation process of the steep wave signal is simulated according to the above process to construct a high-frequency correction unit.

[0039] Based on the actual parameters of the transformer, the multi-order oscillation process of the steep wave signal is simulated to construct a high-frequency correction unit, specifically including: constructing an LC parallel resonance unit to simulate the multi-order oscillation process of the steep wave signal to determine the circuit parameters of each LC parallel resonance unit corresponding to the multi-order oscillation according to the actual parameters of the transformer, wherein the circuit parameters include the capacitance and inductance of the LC parallel resonance unit; according to the circuit parameters of each LC parallel resonance unit corresponding to the multi-order oscillation, multiple LC parallel resonance units are connected in series to determine a multi-order LC parallel resonance circuit corresponding to the multi-order oscillation process; and a specified parallel resistor is introduced into each LC parallel resonance unit of the multi-order LC parallel resonance circuit to construct the high-frequency correction unit.

[0040] In one embodiment of the present specification, an LC parallel resonant circuit is constructed to simulate the process in which a steep wave is reflected at the connection point of the coil and oscillates periodically with the time it takes to propagate back and forth within the coil. Based on the actual parameters of the transformer, the circuit parameters of each LC parallel resonant unit corresponding to the multi-order oscillation are calculated. These circuit parameters include the capacitance and inductance of the LC parallel resonant unit. Based on the circuit parameters of each LC parallel resonant unit corresponding to the multi-order oscillation, the LC parallel resonant unit corresponding to each order of oscillation is constructed. Multiple LC parallel resonant units are connected in series to determine the multi-order LC parallel resonant circuit corresponding to the multi-order oscillation process. A specified parallel resistor is introduced into each LC parallel resonant unit in the multi-order LC parallel resonant circuit to construct the high-frequency correction unit. Figure 2 This is a schematic diagram of the circuit structure of a high-frequency correction unit provided in an embodiment of this specification, such as Figure 2 As shown, L′, C′ and R′ are the circuit parameters of the first parallel resonance unit corresponding to the fundamental oscillation frequency, L2′, C2′ and R′ are the circuit parameters of the second-order parallel resonance unit corresponding to the second-order oscillation frequency, L3′, C3′ and R′ are the circuit parameters of the third-order parallel resonance unit corresponding to the third-order oscillation frequency, and R′ is the specified parallel resistance.

[0041] Determining the circuit parameters of each LC parallel resonant unit corresponding to the multi-order oscillation according to the actual parameters of the transformer, specifically comprising: simulating the fundamental oscillation frequency caused by reflection during the steep wave propagation process according to the actual parameters of the transformer using a first preset formula to determine the first circuit parameters of the first LC parallel resonant unit corresponding to the fundamental oscillation; the first preset formula includes and Wherein, C' is the capacitance of the first LC parallel resonant unit, L' is the inductance of the first LC parallel resonant unit, ε0 represents the dielectric constant of vacuum, ε P represents the relative dielectric constant of the conductor, μ0 represents the magnetic permeability of vacuum, d a Indicates the average diameter of the conductor, h d Indicates the height of the conductor, aP represents the thickness of the turn insulation, and n is the number of turns of the transformer to be simulated. Based on the fundamental oscillation frequency, a high-order resonant frequency corresponding to an integer multiple of the fundamental oscillation frequency is determined, so as to determine the high-order circuit parameters of the high-order LC parallel resonant unit corresponding to the high-order resonant frequency through a second preset formula and the first circuit parameters of the first LC parallel resonant unit. The second preset formula is: Among them, L′ m is the inductance of the m-order LC parallel resonant unit, C′ m is the capacitance of the m-order LC parallel resonant unit. The specified parallel resistance is Where R′ is the specified parallel resistance, ε0 is the dielectric constant of vacuum, and ε P represents the relative dielectric constant of the conductor, μ0 represents the magnetic permeability of vacuum, d a Indicates the average diameter of the conductor, h d Indicates the height of the conductor, a P It represents the thickness of the turn insulation, and σ is the correction factor.

[0042] In one embodiment of the present specification, the resonant frequency f of the circuit is the same as the frequency of the oscillation process: Where C′ and L′ represent the capacitance and inductance of the LC parallel resonant unit, respectively, which are determined by the structural parameters of the tangled winding bifilar unit and can be calculated using the following formula: and Where ε0 represents the dielectric constant of vacuum, ε P represents the relative dielectric constant of the conductor, μ0 represents the magnetic permeability of vacuum, d a Indicates the average diameter of the conductor, h d Indicates the height of the conductor, a P It represents the thickness of the turn insulation, n is the number of turns of the transformer to be simulated, and is related to the structure of the transformer.

[0043] On the basis of considering the fundamental oscillation frequency caused by reflection during the propagation of steep waves, we further consider the higher-order resonant frequency of the integer multiples of the fundamental oscillation frequency, namely: f m =mf(m=2,3), considering the second-order and third-order oscillation processes of the signal, we also simulate it by constructing an LC parallel resonant circuit, and the circuit parameters are calculated using the following formula:

[0044]

[0045] Finally, a parallel resistor R′ is introduced into the LC parallel resonant circuit to simulate the damping of the oscillation process. The calculation method is as follows:

[0046]

[0047] Where σ is a correction factor, generally a positive integer. The correction factor is determined by comparing the winding impedance spectrum simulated by the equivalent circuit model with the measured impedance spectrum. It should be noted that the equivalent circuit model here refers to the final model without the parallel resistor R′. The equivalent circuit model is used to conduct experiments on the transformer to be simulated. The winding impedance spectrum simulated by the equivalent circuit model and the measured impedance spectrum are compared to determine the correction factor. This ensures that the simulated winding impedance spectrum obtained by the model after adding the parallel resistor R′ is closer to the measured impedance spectrum.

[0048] Step S102 : Correcting the pre-built two-wire equivalent circuit unit corresponding to the transformer to be simulated by a high-frequency correction unit to generate a high-frequency equivalent circuit model of the two-wire unit.

[0049] The high-frequency correction unit is used to correct a pre-built two-wire equivalent circuit unit corresponding to the transformer to be simulated to generate a high-frequency equivalent circuit model of the two-wire unit. The method specifically includes: obtaining a two-wire equivalent circuit unit corresponding to the transformer to be simulated, wherein the two-wire equivalent circuit unit includes the resistance, self-inductance and equivalent capacitance of the two-wire unit; and connecting the high-frequency correction unit and the equivalent capacitance in series in the two-wire equivalent circuit unit to generate a high-frequency equivalent circuit model of the two-wire unit.

[0050] In one embodiment of the present specification, an equivalent circuit model of the winding is constructed based on the equivalent model of the bifilar unit. Figure 3 A schematic diagram of the circuit structure of a traditional two-wire pancake equivalent circuit unit provided in the embodiment of this specification is shown in FIG. Figure 3 R, L, C shown DS Respectively represent the resistance, self-inductance and equivalent capacitance of the two-wire unit. The low-voltage winding has a small diameter, a small number of turns, and a short wire length. Figure 2 The error in modeling the traditional equivalent circuit shown is not obvious. However, the diameter of the high-voltage side tangled winding is longer and the number of turns is more. At high frequencies, the length of the coil conductor will be greater than the signal wavelength. Therefore, by Figure 2 The high frequency correction unit shown is Figure 3 The double-wire equivalent circuit unit shown in the figure is modified to obtain the high-frequency equivalent circuit model of the tangled winding double-wire unit. Figure 4 This is a schematic diagram of the circuit structure of a high-frequency equivalent circuit model of a two-wire pancake unit provided in an embodiment of this specification.

[0051] Through the above technical solution, the impedance characteristics of the winding at high frequency are simulated by multiple series RLC parallel resonant units, which significantly improves the frequency upper limit of the model; based on the wave process of high-frequency signal propagation, a high-frequency correction unit of the double-wire equivalent circuit is established, and the double-wire unit of the tangled winding is corrected. The wave process of signal propagation in the winding is taken into account, and the fundamental frequency oscillation, second-order and third-order oscillation of the high-frequency signal propagating in the winding are simulated, which significantly improves the frequency upper limit of the model and can accurately simulate the impedance characteristics of the winding in a frequency range of up to 10MHz.

[0052] Step S103: determining a pre-built designated equivalent circuit model corresponding to the transformer to be simulated.

[0053] The designated equivalent circuit model includes a bifilar equivalent circuit unit, a first transverse capacitance between the iron core and the low-voltage winding, a second transverse capacitance between the low-voltage winding and the high-voltage winding, and a third transverse capacitance between the high-voltage winding and the casing;

[0054] Step S104: construct a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated based on the high-frequency equivalent circuit model of the bifilar unit, the preset fourth transverse capacitance, and the specified equivalent circuit model, so as to simulate the signal propagation of the high-frequency partial discharge current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model.

[0055] A core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated is constructed based on the high-frequency equivalent circuit model of the two-wire disc unit, the preset fourth transverse capacitor, and the designated equivalent circuit model. The method specifically includes: determining the designated equivalent circuit model, wherein the designated equivalent circuit model includes a low-voltage winding unit and a high-voltage winding unit, the low-voltage winding unit includes a plurality of first two-wire disc equivalent circuit units, and the high-voltage winding unit includes a plurality of second two-wire disc equivalent circuit units; replacing the plurality of second two-wire disc equivalent circuit units with the high-frequency equivalent circuit model of the two-wire disc unit, and adding the fourth transverse capacitor to construct the core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated.

[0056] Adding a fourth transverse capacitor specifically includes: adding the fourth transverse capacitor between the high-voltage winding and the core grounding point of the specified equivalent circuit model, wherein the fourth transverse capacitor is a transverse capacitor between the high-voltage winding and the core side yoke.

[0057] In one embodiment of the present specification, a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated is constructed based on a high-frequency equivalent circuit model of a double-wire disc unit, a pre-set fourth transverse capacitance, and a specified equivalent circuit model. The ground capacitance branch of the high-voltage winding in the equivalent circuit model is corrected. On the basis of the traditional model considering the transverse capacitance between the core and the low-voltage winding, between the low-voltage winding and the high-voltage winding, and between the high-voltage winding and the casing, the transverse capacitance between the high-voltage winding and the core yoke is further considered, and the fourth transverse capacitance is added between the high-voltage winding and the core grounding point in the equivalent circuit model. The fourth transverse capacitance here is obtained by finite element simulation based on the transformer structural parameters. Figure 5 This is a schematic diagram of the circuit structure of a core-winding high-frequency equivalent circuit model provided in the embodiment of this specification, such as Figure 5 The high voltage winding and low voltage winding shown in the figure are composed of repeated double-wire units connected in series along the axial direction, R, L, C DS The insulation between the high-voltage winding and the low-voltage winding, between the high-voltage winding and the shell, and between the low-voltage winding and the core is represented by C HL 、C HG 、C LG M represents the mutual inductance between the coils. The multiple second double-coil equivalent circuit units in the high-voltage side tangled winding circuit are replaced with a double-coil unit high-frequency equivalent circuit model with a high-frequency correction unit added. At the same time, a capacitor C is added between the high-voltage winding and the core grounding point. HC To represent the transverse capacitance between the high voltage winding and the core side yoke.

[0058] Through the above technical solution, the lateral capacitance between the high-voltage winding and the core side yoke is taken into consideration, and the ground capacitance branch of the high-voltage winding is improved. This can accurately simulate the current signal at the core grounding point, which is more in line with actual partial discharge detection.

[0059] The signal propagation of the local discharge high-frequency current generated by the transformer to be simulated is simulated through the core-winding high-frequency equivalent circuit model, specifically including: determining multiple component parameters of the core-winding high-frequency equivalent circuit model through the actual transformer parameters of the transformer to be simulated; based on the multiple component parameters, injecting a pulse signal at a specified position of the core-winding high-frequency equivalent circuit model to simulate the local discharge process, so as to determine the signal propagation simulation data of the high-frequency current.

[0060] In one embodiment of the present specification, the actual transformer parameters of the transformer to be simulated are used to determine multiple component parameters of the core-winding high-frequency equivalent circuit model using finite element simulation. Based on the multiple component parameters, a pulse signal is injected into the specified position of the core-winding high-frequency equivalent circuit model to simulate the local discharge process, so as to determine the signal propagation simulation data of the high-frequency current. An experiment is conducted on a laboratory transformer scale model. The core-winding high-frequency equivalent circuit model of the transformer is established according to the above method. The specific circuit parameters can be calculated by finite element simulation based on the structural dimensions of the transformer. An impedance analyzer is connected to the ends of the high-voltage winding of the laboratory transformer to measure the impedance spectrum of the high-voltage winding. At the same time, the impedance spectrum of the high-voltage winding is simulated using the traditional equivalent circuit model and the core-winding high-frequency equivalent circuit model in the embodiment of the present specification. Figure 6 This is a schematic diagram of the simulation and measurement results of the impedance spectrum of a high-voltage winding provided in the embodiment of the specification. A pulse signal is injected into the 10th coil of the high-voltage winding in the laboratory transformer and the simulation model to simulate partial discharge, and the high-frequency current signal is measured at the grounding point of the core. Figure 7 This is a schematic diagram of simulation results and test results of a high-frequency current signal at the core grounding point provided in an embodiment of this specification, wherein: Figure 7 (a) shows two simulation results of the high-frequency current signal at the core grounding point, one is the traditional equivalent circuit model, and the other is the core-winding high-frequency equivalent circuit model in the embodiment of this specification. Figure 7 (b) is the test result of the high-frequency current signal at the core grounding point, that is, the measured value. Figure 6 and Figure 7 As can be seen, compared to traditional models, the core-winding high-frequency equivalent circuit model proposed in the examples of this specification significantly increases the upper frequency limit, accurately simulating the impedance characteristics of the winding within a frequency range up to 10 MHz. It also significantly improves the accuracy of the core grounding signal simulation, resolving the difficulty of traditional models in characterizing the core grounding signal.

[0061] Through the above technical solution, based on the wave process of high-frequency signal propagation, a high-frequency correction unit of the double-pie cake equivalent circuit is established, and the double-pie cake unit of the tangled winding is corrected. The wave process of the signal propagating in the winding is taken into account, and the fundamental frequency oscillation, second-order and third-order oscillation of the high-frequency signal propagating in the winding are simulated, which significantly improves the upper frequency limit of the model and can accurately simulate the impedance characteristics of the winding within a frequency range of up to 10MHz; the lateral capacitance between the high-voltage winding and the core side yoke is taken into account, and the equivalent circuit of the double-pie cake unit of the tangled winding on the high-voltage side is corrected, and the ground capacitance branch of the high-voltage winding is improved, which can accurately simulate the current signal at the grounding point of the core, and is more in line with actual partial discharge detection.

[0062] The embodiment of this specification also provides a transformer current signal simulation device of a circuit model, such as Figure 8 As shown, the device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to:

[0063] Determine the actual parameters of the transformer corresponding to the transformer to be simulated, and based on the actual parameters of the transformer, simulate the multi-order oscillation process of the steep wave signal to construct a high-frequency correction unit; correct the pre-constructed double-pie cake equivalent circuit unit corresponding to the transformer to be simulated through the high-frequency correction unit to generate a high-frequency equivalent circuit model of the double-pie cake unit; determine the pre-constructed specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes the double-pie cake equivalent circuit unit, a first transverse capacitance between the iron core and the low-voltage winding, a second transverse capacitance between the low-voltage winding and the high-voltage winding, and a third transverse capacitance between the high-voltage winding and the casing; construct a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated based on the double-pie cake unit high-frequency equivalent circuit model, a pre-set fourth transverse capacitance and the specified equivalent circuit model, so as to simulate the signal propagation of the partial discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model.

[0064] The embodiments of this specification also provide a non-volatile computer storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured as follows:

[0065] Determine the actual parameters of the transformer corresponding to the transformer to be simulated, and based on the actual parameters of the transformer, simulate the multi-order oscillation process of the steep wave signal to construct a high-frequency correction unit; correct the pre-constructed double-pie cake equivalent circuit unit corresponding to the transformer to be simulated through the high-frequency correction unit to generate a high-frequency equivalent circuit model of the double-pie cake unit; determine the pre-constructed specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes the double-pie cake equivalent circuit unit, a first transverse capacitance between the iron core and the low-voltage winding, a second transverse capacitance between the low-voltage winding and the high-voltage winding, and a third transverse capacitance between the high-voltage winding and the casing; construct a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated based on the double-pie cake unit high-frequency equivalent circuit model, a pre-set fourth transverse capacitance and the specified equivalent circuit model, so as to simulate the signal propagation of the partial discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model.

[0066] The various embodiments in this specification are described in a progressive manner. Similar portions between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the device, apparatus, and non-volatile computer storage medium embodiments are generally similar to the method embodiments, so their descriptions are relatively simplified. For relevant details, refer to the descriptions of the method embodiments.

[0067] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0068] The devices and media provided in the embodiments of this specification correspond one-to-one to the methods. Therefore, the devices and media also have similar beneficial technical effects to their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0069] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems, or computer program products. Therefore, this specification may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0070] This specification is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of this specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0071] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0072] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0073] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0074] Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0075] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0076] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0077] The foregoing description is merely one or more embodiments of this specification and is not intended to limit this specification. It will be apparent to those skilled in the art that various modifications and variations may be made to one or more embodiments of this specification. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of one or more embodiments of this specification are intended to be within the scope of the claims of this specification.

Claims

1. A transformer current signal simulation method for a circuit model, characterized in that: The method comprises: Determine actual transformer parameters corresponding to the transformer to be simulated, and simulate the multi-order oscillation process of the steep wave signal based on the actual transformer parameters to construct a high-frequency correction unit; The high-frequency correction unit is used to correct the pre-built two-wire equivalent circuit unit corresponding to the transformer to be simulated, thereby generating a high-frequency equivalent circuit model of the two-wire unit; Determining a pre-built specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes a two-wire equivalent circuit unit, a first transverse capacitance between the iron core and the low-voltage winding, a second transverse capacitance between the low-voltage winding and the high-voltage winding, and a third transverse capacitance between the high-voltage winding and the casing; According to the high-frequency equivalent circuit model of the double-wire disc unit, the pre-set fourth transverse capacitance and the specified equivalent circuit model, a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated is constructed, so as to simulate the signal propagation of the local discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model, wherein the fourth transverse capacitance is the transverse capacitance between the high-voltage winding and the core side yoke.

2. The transformer current signal simulation method of a circuit model according to claim 1, characterized in that: Based on the actual parameters of the transformer, the multi-order oscillation process of the steep wave signal is simulated to construct a high-frequency correction unit, which specifically includes: Constructing an LC parallel resonant unit and simulating a multi-order oscillation process of a steep wave signal to determine circuit parameters of each of the LC parallel resonant units corresponding to the multi-order oscillation based on actual parameters of the transformer, wherein the circuit parameters include capacitance and inductance of the LC parallel resonant unit; According to the circuit parameters of each of the LC parallel resonance units corresponding to the multi-order oscillation, multiple LC parallel resonance units are connected in series to determine a multi-order LC parallel resonance circuit corresponding to the multi-order oscillation process; In each of the LC parallel resonance units of the multi-stage LC parallel resonance circuit, a prescribed parallel resistance is introduced to configure the high frequency correction unit.

3. The transformer current signal simulation method of a circuit model according to claim 2, characterized in that: Determining circuit parameters of each of the LC parallel resonance units corresponding to the multi-order oscillation according to the actual parameters of the transformer specifically includes: Using a first preset formula and according to the actual parameters of the transformer, the fundamental oscillation frequency caused by reflection during steep wave propagation is simulated to determine first circuit parameters of the first LC parallel resonant unit corresponding to the fundamental oscillation; The first preset formula includes and ,in, is the capacitance of the first LC parallel resonant unit, is the inductance of the first LC parallel resonant unit, represents the dielectric constant of vacuum, represents the relative dielectric constant of the conductor, represents the vacuum permeability, represents the average diameter of the conductor, represents the height of the conductor, Indicates the thickness of the turn insulation, n is the number of turns of the transformer to be simulated; Based on the fundamental oscillation frequency, determining a higher-order resonant frequency corresponding to an integer multiple of the fundamental oscillation frequency, and determining a higher-order circuit parameter of the higher-order LC parallel resonant unit corresponding to the higher-order resonant frequency by using a second preset formula and a first circuit parameter of the first LC parallel resonant unit; The second preset formula is: ,in, is the inductance of the m-order LC parallel resonant unit, is the capacitance of the m-order LC parallel resonant unit.

4. The transformer current signal simulation method of a circuit model according to claim 2, characterized in that: The specified parallel resistance is ,in, To specify the parallel resistance, represents the dielectric constant of vacuum, represents the relative dielectric constant of the conductor, represents the vacuum permeability, represents the height of the conductor, Indicates the thickness of the turn insulation, is the correction factor, n is the number of turns of the transformer to be simulated.

5. The transformer current signal simulation method of a circuit model according to claim 1, characterized in that: The high-frequency correction unit is used to correct the pre-built two-wire equivalent circuit unit corresponding to the transformer to be simulated to generate a high-frequency equivalent circuit model of the two-wire unit, specifically including: Obtaining a two-wire equivalent circuit unit corresponding to the transformer to be simulated, wherein the two-wire equivalent circuit unit includes resistance, self-inductance and equivalent capacitance of the two-wire unit; In the bifilar equivalent circuit unit, the high-frequency correction unit is connected in series with the equivalent capacitor to generate a high-frequency equivalent circuit model of the bifilar unit.

6. The transformer current signal simulation method of a circuit model according to claim 1, characterized in that: Constructing a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated based on the bifilar unit high-frequency equivalent circuit model, the preset fourth transverse capacitor, and the specified equivalent circuit model, specifically comprising: Determining the specified equivalent circuit model, wherein the specified equivalent circuit model includes a low-voltage winding and a high-voltage winding, the low-voltage winding includes a plurality of first two-wire equivalent circuit units, and the high-voltage winding includes a plurality of second two-wire equivalent circuit units; The plurality of second bifilar equivalent circuit units are replaced by the bifilar unit high-frequency equivalent circuit model, and a fourth transverse capacitor is added to construct a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated.

7. The transformer current signal simulation method of a circuit model according to claim 6, characterized in that: Adding a fourth lateral capacitor, specifically including: The fourth transverse capacitor is added between the high-voltage winding and the core grounding point of the specified equivalent circuit model.

8. The transformer current signal simulation method of a circuit model according to claim 1, characterized in that: The signal propagation of the partial discharge high-frequency current generated by the transformer to be simulated is simulated by using the core-winding high-frequency equivalent circuit model, specifically including: Determining multiple component parameters of the core-winding high-frequency equivalent circuit model based on actual transformer parameters of the transformer to be simulated; Based on the multiple component parameters, a pulse signal is injected into a designated position of the core-winding high-frequency equivalent circuit model to simulate a partial discharge process, so as to determine signal propagation simulation data of the high-frequency current.

9. A transformer current signal simulation device for a circuit model, characterized in that: The device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to: Determine actual transformer parameters corresponding to the transformer to be simulated, and simulate the multi-order oscillation process of the steep wave signal based on the actual transformer parameters to construct a high-frequency correction unit; The high-frequency correction unit is used to correct the pre-built two-wire equivalent circuit unit corresponding to the transformer to be simulated, thereby generating a high-frequency equivalent circuit model of the two-wire unit; Determining a pre-built specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes a two-wire equivalent circuit unit, a first transverse capacitance between the iron core and the low-voltage winding, a second transverse capacitance between the low-voltage winding and the high-voltage winding, and a third transverse capacitance between the high-voltage winding and the casing; According to the high-frequency equivalent circuit model of the double-wire disc unit, the pre-set fourth transverse capacitance and the specified equivalent circuit model, a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated is constructed, so as to simulate the signal propagation of the local discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model, wherein the fourth transverse capacitance is the transverse capacitance between the high-voltage winding and the core side yoke.

10. A non-volatile computer storage medium storing computer executable instructions, characterized in that: The computer executable instructions are configured to: Determine actual transformer parameters corresponding to the transformer to be simulated, and simulate the multi-order oscillation process of the steep wave signal based on the actual transformer parameters to construct a high-frequency correction unit; The high-frequency correction unit is used to correct the pre-built two-wire equivalent circuit unit corresponding to the transformer to be simulated, thereby generating a high-frequency equivalent circuit model of the two-wire unit; Determining a pre-built specified equivalent circuit model corresponding to the transformer to be simulated, wherein the specified equivalent circuit model includes a two-wire equivalent circuit unit, a first transverse capacitance between the iron core and the low-voltage winding, a second transverse capacitance between the low-voltage winding and the high-voltage winding, and a third transverse capacitance between the high-voltage winding and the casing; According to the high-frequency equivalent circuit model of the double-wire disc unit, the pre-set fourth transverse capacitance and the specified equivalent circuit model, a core-winding high-frequency equivalent circuit model corresponding to the transformer to be simulated is constructed, so as to simulate the signal propagation of the local discharge high-frequency current generated by the transformer to be simulated through the core-winding high-frequency equivalent circuit model, wherein the fourth transverse capacitance is the transverse capacitance between the high-voltage winding and the core side yoke.

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