Method and device for establishing high-frequency equivalent circuit model of transformer

Abstract

The embodiment of the invention discloses a method and a device for establishing a high-frequency equivalent circuit model of a transformer. The method for establishing the high-frequency equivalent circuit model of the transformer comprises the following steps of: establishing a refined capacitance network model of a transformer winding; performing finite element simulation on the transformer to determine capacitance parameters; and in a preset high-frequency band, eliminating inductance parameters and resistance parameters of the transformer winding, and establishing a high-frequency equivalent circuit model of the transformer based on the capacitance parameters and the refined capacitance network model of the transformer winding. According to the method, the accurate transformer high-frequency equivalent circuit model is established, and the accuracy of high-frequency current simulation can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment state detection and protection, and in particular to a method and device for establishing a high-frequency equivalent circuit model of a transformer. Background Art

[0002] Power transformers are the core equipment for realizing electric energy transmission and distribution in power systems. Their stable operation is related to the power supply quality and economic benefits of power systems. Partial discharge is one of the main types of operating failures of electrical equipment. By sensing and online monitoring of partial discharge inside the transformer, we can obtain information such as the working condition of the transformer and the degree of internal insulation degradation, providing information support for transformer fault prediction and protection strategies. Partial discharge high-frequency current is one of the main measurement parameters for sensing partial discharge of transformers. By equivalentizing a specific model of transformer, its high-frequency equivalent circuit model can be obtained, providing an optimization strategy for transformer sensing detection. The high-frequency equivalent circuit model is an equivalent circuit model of the high-frequency current transmitted inside the transformer when partial discharge occurs in the transformer winding.

[0003] Existing research on the high-frequency equivalent circuit model of the transformer mostly uses the entire winding unit as the modeling unit for simulation modeling, and multiple turns of wire are equivalent to one winding unit, and the turn is not used as a unit for research, so the accuracy of simulation modeling is poor. The existing technology lacks a more accurate solution for establishing the high-frequency equivalent circuit model of the transformer. Summary of the invention

[0004] In order to solve at least one technical problem in the above-mentioned background technology, the present invention proposes a method and device for establishing a high-frequency equivalent circuit model of a transformer.

[0005] In order to achieve the above object, according to one aspect of the present invention, a method for establishing a high-frequency equivalent circuit model of a transformer is provided, the method comprising:

[0006] Establish transformer winding detailed capacitor network model;

[0007] Conduct finite element simulation on the transformer to determine the capacitance parameters;

[0008] In a preset high-frequency frequency band, the inductance parameters and resistance parameters of the transformer winding are omitted, and a high-frequency equivalent circuit model of the transformer is established based on the capacitance parameters and the transformer winding refined capacitance network model.

[0009] Optionally, establishing a transformer winding detailed capacitor network model includes:

[0010] The inter-turn capacitors are arranged in series in a transverse manner according to the order of the turns, and the inter-turn capacitors between the turns at the same position in the upper and lower adjacent coils are arranged in parallel in a longitudinal direction to obtain a winding refinement basic unit;

[0011] The winding refinement basic units are stacked vertically to obtain the transformer winding refinement capacitor network model.

[0012] Optionally, establishing a transformer winding detailed capacitor network model includes:

[0013] In the transformer winding refined capacitance network model, the mutual capacitance between internal structures is taken into consideration, and the partial capacitance networks of each winding are connected on the propagation path, wherein the mutual capacitance between internal structures includes: the inductive mutual capacitance between the low voltage winding and the iron core, the inductive mutual capacitance between the medium voltage winding and the low voltage winding, the inductive mutual capacitance between the high voltage winding and the medium voltage winding, and the inductive mutual capacitance between the high voltage winding and the transformer oil tank casing.

[0014] Optionally, the performing finite element simulation on the transformer to determine the capacitance parameters specifically includes:

[0015] Obtaining a preset capacitor simulation parameter table, wherein the capacitor simulation parameter table records parameter values ​​of various parameters required for capacitor simulation, wherein the various parameters required for capacitor simulation include: winding parameters, core parameters, and oil tank parameters, and the parameter values ​​of the size parameters in the capacitor simulation parameter table are all actual size values;

[0016] A three-dimensional finite element simulation model is established according to the capacitance simulation parameter table, and simulation calculations are performed on the capacitance parameters.

[0017] Optionally, establishing a three-dimensional finite element simulation model according to the capacitance simulation parameter table and performing simulation calculation on the capacitance parameters includes:

[0018] Based on the actual size values ​​in the capacitance simulation parameter table, a finite element simulation calculation is performed using a three-dimensional proportional model to obtain the mutual capacitance between the windings and the mutual capacitance between the windings and other structures;

[0019] Based on the actual size values ​​in the capacitance simulation parameter table, the three-dimensional coil arrangement simulation calculation of the winding is refined to obtain the turn-to-turn capacitance and the pancake-to-pancake capacitance.

[0020] Optionally, the winding parameters include: the radial inner radius of the winding coil, the radial outer radius of the winding coil, the axial height of the winding coil, the total number of turns of each level of winding coil, the total number of winding coils of each level and the inner radius of the sub-conductor of each level of winding coil; the core parameters include: the core style, the core window height, the iron yoke height, the main column diameter, the side column diameter, the lateral distance between the main column and the main column core window, and the lateral distance between the main column and the side column core window; the oil tank parameters include: the length, width and height of the equivalent rectangular parallelepiped of the transformer oil tank and the thickness of the transformer oil tank wall.

[0021] In order to achieve the above object, according to another aspect of the present invention, a device for establishing a high-frequency equivalent circuit model of a transformer is provided, the device comprising:

[0022] A transformer winding detailed capacitor network model establishing unit is used to establish a transformer winding detailed capacitor network model;

[0023] A capacitance parameter determination unit, used for performing finite element simulation on the transformer to determine capacitance parameters;

[0024] The transformer high-frequency equivalent circuit model establishment unit is used to omit the inductance parameters and resistance parameters of the transformer winding in a preset high-frequency frequency band, and establish the transformer high-frequency equivalent circuit model based on the capacitance parameters and the transformer winding refined capacitance network model.

[0025] Optionally, the transformer winding detailed capacitor network model establishing unit includes:

[0026] A winding refinement basic unit generation module is used to arrange the inter-turn capacitors in series in a transverse manner according to the order of turns, and to arrange the inter-cake capacitors between turns at the same position in the upper and lower adjacent coils in parallel in a longitudinal manner to obtain a winding refinement basic unit;

[0027] The basic unit superposition module is used to vertically superimpose the winding refinement basic units to obtain the transformer winding refinement capacitor network model.

[0028] In order to achieve the above-mentioned purpose, according to another aspect of the present invention, a computer device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for establishing a high-frequency equivalent circuit model of a transformer when executing the computer program.

[0029] In order to achieve the above-mentioned purpose, according to another aspect of the present invention, a computer-readable storage medium is further provided, on which a computer program / instruction is stored, and when the computer program / instruction is executed by a processor, the steps of the method for establishing a high-frequency equivalent circuit model of a transformer are implemented.

[0030] In order to achieve the above-mentioned purpose, according to another aspect of the present invention, a computer program product is also provided, including a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned method for establishing a high-frequency equivalent circuit model of a transformer.

[0031] The beneficial effects of the present invention are:

[0032] The embodiment of the present invention establishes a transformer winding refined capacitor network model, and then performs finite element simulation on the transformer to determine the capacitance parameters. Finally, in a preset high-frequency band, the inductance parameters and resistance parameters of the transformer winding are omitted, and a transformer high-frequency equivalent circuit model is established based on the capacitance parameters and the transformer winding refined capacitor network model. Thus, a relatively accurate transformer high-frequency equivalent circuit model is established, which helps to improve the accuracy of high-frequency current simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0034] Figure 1 is a flow chart of a method for establishing a high-frequency equivalent circuit model of a transformer according to an embodiment of the present invention;

[0035] Figure 2 is a flow chart of establishing a transformer winding detailed capacitor network model according to an embodiment of the present invention;

[0036] Figure 3 is a first flow chart of simulating and calculating capacitance parameters according to an embodiment of the present invention;

[0037] Figure 4 is a second flow chart of simulating and calculating capacitance parameters according to an embodiment of the present invention;

[0038] Figure 5 Schematic diagram of high frequency equivalent circuit of an embodiment of the present invention

[0039] Figure 6 1. It is a schematic diagram of a winding refinement basic unit according to an embodiment of the present invention;

[0040] Figure 7 It is a structural block diagram of a device for establishing a high-frequency equivalent circuit model of a transformer according to an embodiment of the present invention;

[0041] Figure 8 It is a schematic diagram of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0043] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0044] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0045] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] The present invention proposes a method for establishing a high-frequency equivalent circuit model of a power transformer, which can be used to equalize the high-frequency discharge capacitive circuit inside the winding according to the actual parameters of the real transformer, make up for the simulation error caused by the overall replacement of the winding by the existing method, and provide technical support for the study of the propagation of high-frequency current inside the winding. In addition, the transformer high-frequency equivalent circuit model of the present invention ignores the influence of resistance and inductance under specific high-frequency conditions, performs high-frequency simulation through a capacitor network structure, and considers the inter-turn capacitance, inter-pancake capacitance, and spatial stray capacitance of the power transformer winding to construct a full capacitor equivalent network, which makes up for the lack of discharge energy calculation in the existing simulation method.

[0047] Figure 5 is a high frequency equivalent circuit diagram, such as Figure 5As shown, taking an AC power transformer containing three voltage level windings of low, medium and high as an example, the low voltage winding is spiral, and its high frequency capacitor network is composed only of longitudinal inter-pancake capacitors; for medium voltage winding and high voltage winding, since one pancake contains multiple turns of winding (5 turns in the figure), the structural capacitance of each pancake unit is equivalent to 4 transverse inter-turn capacitors and 5 longitudinal inter-pancake capacitors, and the capacitance network of the entire winding is composed of superimposed pancake units.

[0048] Figure 1 : is a flow chart of a method for establishing a high-frequency equivalent circuit model of a transformer according to an embodiment of the present invention. Figure 1 As shown, in one embodiment of the present invention, the method for establishing a high-frequency equivalent circuit model of a transformer of the present invention includes steps S101 to S103.

[0049] Step S101, establishing a transformer winding detailed capacitor network model.

[0050] The existing methods for constructing transformer equivalent circuit models all treat the winding part as a whole, without considering the internal structure of the winding. In the study of high-frequency current transfer, it is necessary to consider the fault location in the winding and the energy characteristics of the high-frequency current, and the method of replacing the winding as a whole is no longer applicable. The present invention takes into account the number of turns and the number of coils of the power transformer winding, constructs an equivalent capacitance network of the refined winding coil, and expresses the capacitance relationship between each turn and each coil in the model, thereby improving the fault point selectivity and making the high-frequency energy transfer simulation in the winding more accurate.

[0051] Step S102: Perform finite element simulation on the transformer to determine capacitance parameters.

[0052] The present invention can simulate and calculate the capacitance parameters of the transformer by establishing a three-dimensional finite element simulation model. The capacitance parameters may specifically include: mutual capacitance between windings, mutual capacitance between windings and other structures, turn-to-turn capacitance, and inter-pancake capacitance. The mutual capacitance between windings includes: mutual capacitance between medium-voltage windings and low-voltage windings, and mutual capacitance between high-voltage windings and medium-voltage windings. The mutual capacitance between windings and other structures includes: mutual capacitance between low-voltage windings and iron cores, and mutual capacitance between high-voltage windings and transformer oil tank casings.

[0053] Step S103, in a preset high frequency band, the inductance parameter and the resistance parameter of the transformer winding are omitted, and a high frequency equivalent circuit model of the transformer is established based on the capacitance parameter and the transformer winding refined capacitance network model.

[0054] In the present invention, in a preset high frequency band, the high frequency equivalent circuit model of the transformer is actually a full capacitance equivalent circuit model of the transformer winding.

[0055] In one embodiment of the present invention, the present invention performs simulation in simulation software based on the capacitance parameters and the transformer winding refined capacitance network model to obtain a transformer high-frequency equivalent circuit model. Specifically, the transformer winding refined capacitance network model is established in the simulation software, and then the capacitance parameters are substituted for simulation to obtain a full capacitance equivalent circuit model of the transformer winding, that is, a transformer high-frequency equivalent circuit model.

[0056] Existing simulations do not make targeted adjustments to frequency. The present invention proposes a circuit equivalence method under high frequency. This method analyzes the high-frequency signal transmission characteristics and the winding circuit structure, eliminates the inductance and resistance parameters of the winding under specific high-frequency conditions, and constructs a full-capacitance equivalent circuit of the power transformer winding, thereby greatly reducing the calculation amount of high-frequency simulation.

[0057] In an optional embodiment of the present invention, the preset high-frequency frequency band may specifically be a high-frequency frequency band from 3 MHz to 30 MHz.

[0058] The present invention aims at the physical parameters of high-frequency current of power transformers. Under the conditions of frequency band of 3MHz to 30MHz and wavelength of 10 to 100m, the finite element simulation analysis using high-frequency model can improve the calculation accuracy, but the large amount of calculation is not conducive to engineering application. In order to accurately capture the behavior of electromagnetic waves on different media and structural interfaces, detailed grid division is still required, which greatly increases the number of grids. At the same time, in the time domain simulation method, the time step needs to be small enough to accurately capture the changes of electromagnetic waves, which greatly increases the amount of calculation. Therefore, the field-path combination method is selected for research and analysis after comprehensive consideration. The length of each turn of the high-voltage winding of a large power transformer is much larger than the distance between adjacent turns. The former is about 3 to 8 meters, while the latter is generally less than 10mm. Therefore, the main propagation direction of the high-frequency signal in the winding is along the axial direction of the winding, that is, the direction of the winding cross section, rather than along the length direction of the wire.

[0059] Under the above conditions, each turn of wire in the transformer winding can be regarded as a transmission line, and the entire winding therefore constitutes a multi-conductor network. Using the simulation model of the continuous disc 6.6kV transformer winding, the transfer characteristics of the partial discharge signal in the frequency range of 1 to 2000kHz were studied, and it was found that the influence of conductivity and resistance in this frequency band can be ignored. Under high-frequency conditions, the dielectric constant of transformer oil is relatively stable, and is less affected by frequency. The capacitance value is relatively stable and can be approximately regarded as a constant. For the frequency bandwidth of 3MHz to 30MHz, the inductance value varies greatly. Considering the inductance and resistance parameters at high frequencies will greatly increase the amount of calculation. Therefore, in this frequency band, the present invention only considers the capacitance parameters in the transformer winding structure. Taking all the above factors into consideration, the multi-conductor model is optimized to obtain a transformer multi-capacitor network model suitable for this study.

[0060] In one embodiment of the present invention, after the transformer high-frequency equivalent circuit model is established, the high-frequency current transfer characteristics of the transformer when partial discharge occurs can be studied based on the transformer high-frequency equivalent circuit model. Since the transformer high-frequency equivalent circuit model of the present invention is established based on the transformer winding refinement capacitor network, the transformer winding refinement capacitor network can show the capacitance relationship between each turn and each pancake in the model, so the selectivity of the fault point is greatly increased, which helps to make the simulation more accurate.

[0061] like Figure 2 As shown, in one embodiment of the present invention, the step S101 of establishing a transformer winding detailed capacitor network model specifically includes step S201 and step S202.

[0062] Step S201, the inter-turn capacitors are arranged in series transversely in the order of turns, and the inter-turn capacitors between turns at the same position in upper and lower adjacent coils are arranged in parallel longitudinally in sequence to obtain a winding refinement basic unit.

[0063] In one embodiment of the present invention, when constructing a transformer winding thinning capacitor network, the inter-turn capacitors are arranged in series in a transverse manner according to the order of turns, and the inter-cake capacitors between the turns at the same position in the upper and lower adjacent coils are arranged in parallel in a longitudinal direction in sequence, so as to construct a basic unit of the thinning winding, which can be specifically as follows: Figure 6 shown.

[0064] Step S202: vertically superimpose the winding refinement basic units to obtain the transformer winding refinement capacitor network model.

[0065] In the present invention, all detailed models of a whole winding can be regarded as a longitudinal superposition of this basic unit.

[0066] It can be seen that the present invention proposes a transformer winding refinement simulation method, which takes into account the number of turns and the number of coils of the real transformer winding, builds a high-frequency equivalent capacitor circuit, and improves the accuracy of high-frequency current simulation.

[0067] In one embodiment of the present invention, the establishment of the transformer winding detailed capacitor network model in step S101 specifically includes:

[0068] In the transformer winding refined capacitance network model, the mutual capacitance between internal structures is taken into consideration, and the partial capacitance networks of each winding are connected on the propagation path, wherein the mutual capacitance between internal structures includes: the inductive mutual capacitance between the low voltage winding and the iron core, the inductive mutual capacitance between the medium voltage winding and the low voltage winding, the inductive mutual capacitance between the high voltage winding and the medium voltage winding, and the inductive mutual capacitance between the high voltage winding and the transformer oil tank casing.

[0069] The present invention also considers the inductive transmission of high-frequency current signals between different windings, between windings and shells, and between the innermost winding and the core when partial discharge occurs in a multi-winding transformer, and takes the inductive transmission process into consideration by supplementing the internal structure mutual capacitance in the capacitor network. Taking into account the transmission mode of the signal, each mutual capacitance is calculated using the actual structural dimensions of the transformer and is set in the capacitor network, so that the windings of different voltage levels and working conditions are combined with the three grounding measurement points of the bushing, transformer oil tank, and core, expanding the research scope of the propagation of high-frequency current signals. Under this method, a high-frequency equivalent circuit model considering its structural characteristics can be formed for each transformer with different parameters, which greatly improves the speed and equivalence of the local discharge high-frequency current simulation and provides a reference for the transformer high-frequency current test.

[0070] like Figure 5 As shown, the present invention is based on different measurement points when measuring high-frequency current in an actual transformer. The mutual capacitance between internal structures is taken into consideration in the equivalent capacitance network, and the capacitance networks of each winding part are connected on the propagation path, specifically including: low-voltage winding-iron core inductive mutual capacitance, medium-voltage winding-low-voltage winding inductive mutual capacitance, high-voltage winding-medium-voltage winding inductive mutual capacitance, and outermost winding (high-voltage winding)-transformer oil tank casing inductive mutual capacitance.

[0071] The mutual capacitance type in the equivalent circuit model described in the present invention is synchronously selected according to the grounding wire measurement point of each type of transformer during the actual high-frequency current test. When building the capacitor network, the high-frequency structure capacitance is added to the capacitor loop according to the installation positions of the high-frequency current sensors such as the shell grounding, the bushing grounding, and the core grounding. Compared with the existing equivalent method that only refines the winding part, the method of this patent connects the structures to form a high-frequency current propagation loop, and combines it with the high-frequency refinement of the winding and the induction between the windings, so that the simulation of the high-frequency current propagation characteristics is more equivalent and accurate.

[0072] like Figure 3 As shown, in one embodiment of the present invention, the above step S102 of performing finite element simulation on the transformer to determine the capacitance parameters specifically includes step S301 and step S302.

[0073] Step S301, obtaining a preset capacitor simulation parameter table, wherein the capacitor simulation parameter table records parameter values ​​of various parameters required for capacitor simulation, including winding parameters, core parameters, and tank parameters, and the parameter values ​​of the size parameters in the capacitor simulation parameter table are all actual size values.

[0074] Step S302: establishing a three-dimensional finite element simulation model according to the capacitance simulation parameter table, and performing simulation calculation on the capacitance parameters.

[0075] The existing transformer simulation design focuses on qualitative restoration of the general structure, but rarely restores the size and structure of the real transformer in proportion. The present invention establishes a three-dimensional finite element simulation model based on the actual size and structure data of the real transformer, simulates and calculates the required capacitance parameters in the high-frequency equivalent capacitance network, and improves the accuracy of the simulation.

[0076] The method for establishing a high-frequency equivalent circuit model of a transformer of the present invention determines that when a high-frequency current simulation model is quickly constructed, for the parameter types required for each type of transformer, when a high-frequency current simulation is performed on a certain transformer, the corresponding parameters are obtained according to the capacitor simulation parameter table, so that a capacitive loop can be quickly constructed and the high-frequency current signal can be analyzed.

[0077] In one embodiment of the present invention, the winding parameters include: the radial inner radius of the winding coil, the radial outer radius of the winding coil, the axial height of the winding coil, the total number of turns of each level of the winding coil, the total number of coils of each level of the winding coil, and the inner radius of the sub-conductor of each level of the winding coil; the core parameters include: the core style, the core window height, the iron yoke height, the main column diameter, the side column diameter, the lateral distance between the main column and the main column core window, and the lateral distance between the main column and the side column core window; the oil tank parameters include: the length, width and height of the equivalent rectangular parallelepiped of the transformer oil tank and the thickness of the transformer oil tank wall.

[0078] In one embodiment of the present invention, the capacitance simulation parameter table may be specifically shown in Table 1:

[0079]

[0080] Table 1

[0081] As shown in Table 1, the parameter table required for building a simulation circuit determined by the present invention is obtained. For a specific transformer, the parameters shown in this table are obtained, and the simulation values ​​of the turn-to-turn, pancake-to-pancake capacitance and the mutual capacitance between structures are quickly obtained through the simulation method, providing data support for building a high-frequency equivalent circuit. The present invention reasonably analyzes and simplifies the transformer structure, selects finite parameters to construct an equivalent simulation model to obtain the capacitance value, and all the capacitance values ​​are involved in the construction of the equivalent capacitance network.

[0082] like Figure 4 As shown, in one embodiment of the present invention, the above steps of establishing a three-dimensional finite element simulation model according to the capacitance simulation parameter table and performing simulation calculation on the capacitance parameters specifically include step S401 and step S402.

[0083] Step S401 : performing finite element simulation calculation using a three-dimensional geometric model based on actual size values ​​in the capacitance simulation parameter table to obtain mutual capacitance between windings and mutual capacitance between windings and other structures.

[0084] Step S402, based on the actual size values ​​in the capacitance simulation parameter table, a three-dimensional coil arrangement simulation calculation is performed to obtain the turn-to-turn capacitance and the pancake-to-pancake capacitance.

[0085] It can be seen that the present invention establishes a three-dimensional finite element simulation model according to the actual size and structure data of the real transformer to simulate and calculate the capacitance parameters, thereby improving the accuracy of the capacitance parameter calculation.

[0086] It can be seen from the above embodiments that the present invention proposes for the first time a high-frequency equivalent circuit model of a large power transformer and a method for establishing the same. The present invention eliminates the resistance and inductance parameters of the winding at a specific high frequency, constructs a full-capacitor equivalent capacitance network, reduces the amount of calculation for high-frequency simulation, and the capacitance network is also convenient for simulating turn-to-turn faults at different locations, thereby increasing the degree of freedom of high-frequency input signal simulation settings. The various capacitance parameters in the capacitance network of the present invention are obtained by designing and calculating a finite element simulation model based on the size data of the real transformer. The turn-to-turn and pancake capacitances in the network are obtained through simulation in a completely three-dimensionally refined manner, rather than using the existing modeling method of treating the entire winding part as a closed whole. The various capacitances calculated by the improved method are close to the measured values, making the full-capacitor simulation network more accurate.

[0087] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0088] Based on the same inventive concept, an embodiment of the present invention also provides a device for establishing a high-frequency equivalent circuit model of a transformer, which can be used to implement the method for establishing a high-frequency equivalent circuit model of a transformer described in the above embodiment, as described in the following embodiment. Since the principle of solving the problem by the device for establishing a high-frequency equivalent circuit model of a transformer is similar to that of the method for establishing a high-frequency equivalent circuit model of a transformer, the embodiment of the device for establishing a high-frequency equivalent circuit model of a transformer can refer to the embodiment of the method for establishing a high-frequency equivalent circuit model of a transformer, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0089] Figure 7 : is a structural block diagram of a device for establishing a high-frequency equivalent circuit model of a transformer according to an embodiment of the present invention. Figure 7 As shown, in one embodiment of the present invention, the transformer high-frequency equivalent circuit model establishment device of the present invention includes:

[0090] A transformer winding detailed capacitor network model establishing unit 1 is used to establish a transformer winding detailed capacitor network model;

[0091] Capacitance parameter determination unit 2, used for performing finite element simulation on the transformer to determine capacitance parameters;

[0092] The transformer high-frequency equivalent circuit model establishing unit 3 is used to omit the inductance parameters and resistance parameters of the transformer winding in a preset high-frequency frequency band, and establish the transformer high-frequency equivalent circuit model based on the capacitance parameters and the transformer winding refined capacitance network model.

[0093] In one embodiment of the present invention, the transformer winding detailed capacitor network model establishing unit 1 specifically includes:

[0094] A winding refinement basic unit generation module is used to arrange the inter-turn capacitors in series in a transverse manner according to the order of turns, and to arrange the inter-cake capacitors between turns at the same position in the upper and lower adjacent coils in parallel in a longitudinal manner to obtain a winding refinement basic unit;

[0095] The basic unit superposition module is used to vertically superimpose the winding refinement basic units to obtain the transformer winding refinement capacitor network model.

[0096] In one embodiment of the present invention, the transformer winding detailed capacitor network model establishing unit 1 specifically includes:

[0097] The mutual capacitance setting module is used to take into account the mutual capacitance between internal structures in the transformer winding refinement capacitance network model, and connect the partial capacitance networks of each winding on the propagation path, wherein the mutual capacitance between internal structures includes: the inductive mutual capacitance between the low voltage winding and the iron core, the inductive mutual capacitance between the medium voltage winding and the low voltage winding, the inductive mutual capacitance between the high voltage winding and the medium voltage winding, and the inductive mutual capacitance between the high voltage winding and the transformer oil tank shell.

[0098] In one embodiment of the present invention, the capacitance parameter determination unit 2 specifically includes:

[0099] A parameter table acquisition module is used to acquire a preset capacitor simulation parameter table, wherein the capacitor simulation parameter table records parameter values ​​of various parameters required for capacitor simulation, wherein the various parameters required for capacitor simulation include: winding parameters, core parameters, and tank parameters, and the parameter values ​​of the size parameters in the capacitor simulation parameter table are all actual size values;

[0100] The finite element simulation module is used to establish a three-dimensional finite element simulation model according to the capacitance simulation parameter table and perform simulation calculation on the capacitance parameters.

[0101] In one embodiment of the present invention, the winding parameters include: the radial inner radius of the winding coil, the radial outer radius of the winding coil, the axial height of the winding coil, the total number of turns of each level of winding coil, the total number of coil cakes of each level of winding coil and the inner radius of the sub-conductor of each level of winding coil; the core parameters include: core style, core window height, iron yoke height, main column diameter, side column diameter, lateral distance between the main column and the main column core window, and lateral distance between the main column and the side column core window; the oil tank parameters include: the length, width and height of the equivalent rectangular parallelepiped of the transformer oil tank and the thickness of the transformer oil tank wall.

[0102] In one embodiment of the present invention, the finite element simulation module specifically includes:

[0103] A first simulation calculation submodule is used to perform finite element simulation calculation using a three-dimensional geometric model based on actual size values ​​in the capacitance simulation parameter table to obtain mutual capacitance between windings and mutual capacitance between windings and other structures;

[0104] The second simulation calculation submodule is used to obtain the turn-to-turn capacitance and the pancake-to-pancake capacitance by performing a simulation calculation of a detailed winding three-dimensional coil arrangement based on the actual size values ​​in the capacitance simulation parameter table.

[0105] In order to achieve the above object, according to another aspect of the present application, a computer device is also provided. Figure 8 As shown, the computer device includes a memory, a processor, a communication interface and a communication bus. A computer program that can be executed on the processor is stored in the memory. When the processor executes the computer program, the steps in the above-mentioned embodiment method are implemented.

[0106] The processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0107] The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer executable programs and units, such as the corresponding program units in the above method embodiments of the present invention. The processor executes various functional applications of the processor and works data processing by running the non-transitory software programs, instructions and modules stored in the memory, that is, implementing the method in the above method embodiments.

[0108] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0109] The one or more units are stored in the memory, and when executed by the processor, the method in the above embodiment is performed.

[0110] The specific details of the above-mentioned computer device can be understood by referring to the corresponding related descriptions and effects in the above-mentioned embodiments, and will not be repeated here.

[0111] In order to achieve the above purpose, according to another aspect of the present application, a computer-readable storage medium is also provided, wherein the computer-readable storage medium stores a computer program, and the computer program implements the steps in the above transformer high-frequency equivalent circuit model establishment method when executed in a computer processor. Those skilled in the art can understand that the implementation of all or part of the process in the above embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and the program can include the process of the embodiment of each method as described above when executed. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (Flash Memory), a hard disk (Hard Disk Drive, abbreviated: HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memory.

[0112] In order to achieve the above-mentioned purpose, according to another aspect of the present application, a computer program product is also provided, including a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned method for establishing a high-frequency equivalent circuit model of a transformer.

[0113] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, and optionally, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for establishing a high-frequency equivalent circuit model of a transformer, characterized in that: include: Establish transformer winding detailed capacitor network model; Conduct finite element simulation on the transformer to determine the capacitance parameters; In a preset high-frequency frequency band, the inductance parameters and resistance parameters of the transformer winding are omitted, and a high-frequency equivalent circuit model of the transformer is established based on the capacitance parameters and the transformer winding refined capacitance network model.

2. The method for establishing a high-frequency equivalent circuit model of a transformer according to claim 1, characterized in that: The step of establishing a transformer winding detailed capacitor network model comprises: The inter-turn capacitors are arranged in series in a transverse manner according to the order of the turns, and the inter-turn capacitors between the turns at the same position in the upper and lower adjacent coils are arranged in parallel in a longitudinal direction to obtain a winding refinement basic unit; The winding refinement basic units are stacked vertically to obtain the transformer winding refinement capacitor network model.

3. The method for establishing a high-frequency equivalent circuit model of a transformer according to claim 1, characterized in that: The step of establishing a transformer winding detailed capacitor network model comprises: In the transformer winding refined capacitance network model, the mutual capacitance between internal structures is taken into consideration, and the partial capacitance networks of each winding are connected on the propagation path, wherein the mutual capacitance between internal structures includes: the inductive mutual capacitance between the low voltage winding and the iron core, the inductive mutual capacitance between the medium voltage winding and the low voltage winding, the inductive mutual capacitance between the high voltage winding and the medium voltage winding, and the inductive mutual capacitance between the high voltage winding and the transformer oil tank casing.

4. The method for establishing a high-frequency equivalent circuit model of a transformer according to claim 1, characterized in that: The method of performing finite element simulation on the transformer to determine capacitance parameters includes: Obtaining a preset capacitor simulation parameter table, wherein the capacitor simulation parameter table records parameter values ​​of various parameters required for capacitor simulation, wherein the various parameters required for capacitor simulation include: winding parameters, core parameters, and oil tank parameters, and the parameter values ​​of the size parameters in the capacitor simulation parameter table are all actual size values; A three-dimensional finite element simulation model is established according to the capacitance simulation parameter table, and simulation calculations are performed on the capacitance parameters.

5. The method for establishing a high-frequency equivalent circuit model of a transformer according to claim 4, characterized in that: The three-dimensional finite element simulation model is established according to the capacitance simulation parameter table, and the capacitance parameters are simulated and calculated, including: Based on the actual size values ​​in the capacitance simulation parameter table, a finite element simulation calculation is performed using a three-dimensional proportional model to obtain the mutual capacitance between the windings and the mutual capacitance between the windings and other structures; Based on the actual size values ​​in the capacitance simulation parameter table, the three-dimensional coil arrangement simulation calculation of the winding is refined to obtain the turn-to-turn capacitance and the pancake-to-pancake capacitance.

6. The method for establishing a high-frequency equivalent circuit model of a transformer according to claim 4, characterized in that: The winding parameters include: the radial inner radius of the winding coil, the radial outer radius of the winding coil, the axial height of the winding coil, the total number of turns of each level of winding coil, the total number of coil cakes of each level of winding coil and the inner radius of the sub-conductor of each level of winding coil; the core parameters include: the core style, the core window height, the iron yoke height, the main column diameter, the side column diameter, the lateral distance between the main column and the main column core window, and the lateral distance between the main column and the side column core window; the oil tank parameters include: the length, width and height of the equivalent rectangular parallelepiped of the transformer oil tank and the thickness of the transformer oil tank wall.

7. A device for establishing a high-frequency equivalent circuit model of a transformer, characterized in that: include: A transformer winding detailed capacitor network model establishing unit is used to establish a transformer winding detailed capacitor network model; A capacitance parameter determination unit, used for performing finite element simulation on the transformer to determine capacitance parameters; The transformer high-frequency equivalent circuit model establishment unit is used to omit the inductance parameters and resistance parameters of the transformer winding in a preset high-frequency frequency band, and establish the transformer high-frequency equivalent circuit model based on the capacitance parameters and the transformer winding refined capacitance network model.

8. The transformer high-frequency equivalent circuit model establishment device according to claim 7, characterized in that: The transformer winding detailed capacitor network model establishing unit comprises: A winding refinement basic unit generation module is used to arrange the inter-turn capacitors in series in a transverse manner according to the order of turns, and to arrange the inter-cake capacitors between turns at the same position in the upper and lower adjacent coils in parallel in a longitudinal manner to obtain a winding refinement basic unit; The basic unit superposition module is used to vertically superimpose the winding refinement basic units to obtain the transformer winding refinement capacitor network model.

9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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