Dry-type air-core reactor temperature rise effect analysis method considering high-frequency harmonic influence and related device

Abstract

The invention provides a dry-type air-core reactor temperature rise effect analysis method considering high-frequency harmonic influence and a related device. The method comprises the following steps: establishing a reactor simulation model and boundary conditions thereof, wherein the model is divided into a physical model and a mathematical model; the physical model generates structural parameters required by calculation, and the mathematical model calculates the temperature distribution of the reactor according to the parameters. Based on set boundary conditions, the simulation model is calculated under harmonic voltages of different frequencies, temperature distribution of the reactor under different frequencies is obtained, and temperature rise analysis is carried out according to the temperature distribution. By means of the method, the temperature rise effect of the reactor in the high-frequency harmonic environment can be accurately evaluated, the accuracy and reliability of thermal performance evaluation can be improved, the temperature rise condition of the reactor in actual operation can be more accurately predicted, and design optimization and operation safety improvement are facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of reactors, and in particular relates to a method for analyzing temperature rise effects of dry-type air-core reactors taking into account the influence of high-frequency harmonics and a related device. Background Art

[0002] With the transformation of the global energy structure, new clean energy sources such as solar energy, wind energy, and tidal energy have been widely used. These clean energy sources are usually connected to the power system through nonlinear devices, resulting in a significant increase in the content of high-order harmonics in the system exceeding 20 times. This not only increases the complexity of the power system, but also poses new challenges to the stability and reliability of the power system, especially in the control of harmonic power in a wide frequency range (about 3~50 times).

[0003] As an important component of the power system, dry-type air-core reactors undertake the important tasks of compensating reactive power, limiting short-circuit current and filtering harmonics. However, with the increase of high-order harmonic content in the power system, reactors face a more severe operating environment. In order to ensure the safe and stable operation of the power system, the reactor must be able to maintain good performance under high-order harmonic conditions, which puts higher requirements on the design and technology of the reactor.

[0004] At present, although there are many methods for the design and analysis of reactors, the research on the temperature rise effect of reactors under high-order harmonics is still not in-depth enough. Existing technologies often ignore the impact of high-order harmonics on the temperature distribution of reactors, and lack effective simulation methods to accurately predict the temperature rise of reactors under high-order harmonics. In addition, the existing analysis methods are difficult to fully reflect the thermal behavior of reactors in actual operation, which limits the application effect of reactors in complex power grid environments. Summary of the invention

[0005] In view of this, the present invention provides a method and related device for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics. By simulating and analyzing the field-loop and flow-heat coupling characteristics of the dry-type air-core reactor, the influence of high-order harmonics on the temperature distribution of the reactor can be effectively evaluated. The present invention aims to more accurately determine the specific influence of high-order harmonic voltage on the packaging temperature of the reactor, thereby improving the design level and operation reliability of the reactor.

[0006] In order to achieve the above object, the technical solution provided by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics, comprising the following steps:

[0008] Acquire the simulation boundary conditions of the reactor simulation model; the reactor simulation model includes a reactor structure physical model and a reactor structure mathematical model, the reactor structure physical model is used to generate the structural parameters required for calculation, and the reactor structure mathematical model is used to calculate the temperature distribution of the reactor according to the structural parameters;

[0009] Based on the simulation boundary conditions, the reactor simulation model is simulated and calculated under the harmonic voltages of different frequencies to obtain the reactor temperature distribution under the influence of harmonics of different frequencies;

[0010] The temperature rise analysis of the reactor is carried out based on the reactor temperature distribution at different frequencies.

[0011] Furthermore, the reactor structure physical model is a two-dimensional simulation model with the wire turn as the basic simulation unit, and the reactor temperature distribution is the reactor coil encapsulation temperature distribution. The construction process of the reactor structure physical model includes:

[0012] Construct a three-dimensional model of the reactor according to the geometric parameters of the reactor;

[0013] Divide different coil layers in the three-dimensional model according to the number of coil layers;

[0014] By using the axisymmetry of the reactor, the three-dimensional model is simplified into a two-dimensional model that only retains the cross section of the coil conductor on one side.

[0015] The turns of each layer of coil are connected in series to obtain a single-layer coil winding;

[0016] The single-layer coil winding is divided into encapsulated windings to obtain a two-dimensional simulation model with turns as basic simulation units.

[0017] Further, the temperature rise analysis of the reactor is performed according to the temperature distribution of the reactor at different frequencies, and also includes:

[0018] According to the reactor encapsulation insulation temperature limit, the reactor coil encapsulation temperature distribution under the influence of harmonics is filtered to obtain the reactor coil encapsulation insulation overheating distribution that exceeds the insulation temperature limit;

[0019] The temperature analysis of the reactor encapsulation insulation is carried out based on the overheat distribution of the reactor coil encapsulation insulation.

[0020] Furthermore, the mathematical model of the reactor structure includes a field-circuit coupling model, and the expression of the field-circuit coupling model is as follows:

[0021] The windings of each layer of coils satisfy the following formula:

[0022]

[0023] In the formula, A θis the circumferential component of the vector magnetic potential A; θ, z, r represent the angle, axial coordinate and radius in the cylindrical coordinate system respectively; μ is the magnetic permeability of the aluminum wire; J θ is the current density flowing through each layer of winding;

[0024] The circuit equation satisfied by the i-th layer winding is as follows:

[0025]

[0026] Where U i ,I i and R i is the voltage, current and resistance of the i-th winding, φ i , A i N is the flux linkage and magnetic potential of each layer of winding; i is the number of turns of the i-th coil.

[0027] Furthermore, the reactor structure mathematical model also includes a flow-heat coupling model, which includes a three-dimensional steady-state heat conduction equation of the reactor. The three-dimensional steady-state heat conduction equation of the reactor is as follows:

[0028]

[0029] In the formula, It is the ratio of thermal conductivity to the product of specific heat capacity and material density; is the ratio of the heat source intensity to the product of specific heat capacity and material density; T is the surface temperature of each layer of winding; x, y and z represent spatial coordinates; t represents time.

[0030] Furthermore, the fluid-heat coupling model also includes the fluid control equation, which is as follows:

[0031]

[0032] In the formula, is the air density; u, v, w are the components of the fluid velocity in the x, y, z directions; F x 、F y 、F z is the component of body force in x, y, and z directions; and are normal stress and shear stress; u is the fluid velocity vector; T is the temperature; is the thermal conductivity of air; is the specific heat capacity; is the fluid temperature; S is the air viscosity dissipation term.

[0033] Furthermore, the setting of simulation boundary conditions at least includes:

[0034] Initial temperature setting, fluid dynamics parameter setting, boundary setting and multiphysics coupling setting.

[0035] In a second aspect, the present invention provides a device for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics, comprising:

[0036] A simulation parameter acquisition module is used to obtain simulation boundary conditions of a reactor simulation model; the reactor simulation model includes a reactor structure physical model and a reactor structure mathematical model, the reactor structure physical model is used to generate structural parameters required for calculation, and the reactor structure mathematical model is used to calculate the temperature distribution of the reactor according to the structural parameters;

[0037] A simulation module is used to simulate and calculate the reactor simulation model under harmonic voltages of different frequencies based on simulation boundary conditions to obtain the reactor temperature distribution under the influence of harmonics of different frequencies;

[0038] The temperature rise analysis module is used to perform temperature rise analysis of the reactor based on the temperature distribution of the reactor at different frequencies.

[0039] In a third aspect, the present invention provides a computer device, the device comprising a processor and a memory:

[0040] The memory is used to store the computer program and send the instructions of the computer program to the processor;

[0041] The processor executes a method for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics according to the instructions of the computer program as described in the first aspect.

[0042] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics as in the first aspect.

[0043] In summary, the present invention provides a method and related device for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics, including obtaining simulation boundary conditions of a reactor simulation model; the reactor simulation model includes a reactor structure physical model and a reactor structure mathematical model, the reactor structure physical model is used to generate the structural parameters required for calculation, and the reactor structure mathematical model is used to calculate the temperature distribution of the reactor according to the structural parameters; based on the simulation boundary conditions, the reactor simulation model is simulated and calculated under harmonic voltages of different frequencies to obtain the temperature distribution of the reactor under the influence of harmonics of different frequencies; based on the temperature distribution of the reactor of different frequencies, the temperature rise analysis of the reactor is performed. The present invention establishes a dry-type air-core reactor simulation model, sets corresponding boundary conditions, and performs simulation calculations under harmonic voltages of different frequencies, thereby accurately analyzing the temperature rise effect of the reactor and improving the accuracy and reliability of the thermal performance evaluation of the reactor in a high-frequency harmonic environment. This method and device can more accurately predict the temperature rise of the reactor in actual operation, which is helpful for optimizing the design and improving the safety of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic flow chart of a method for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics provided in an embodiment of the present invention;

[0046] Figure 2 A structural diagram of a dry-type air-core reactor provided in an embodiment of the present invention;

[0047] Figure 3 A two-dimensional simulation model diagram of a reactor provided in an embodiment of the present invention;

[0048] Figure 4 The reactor coil encapsulation temperature distribution under the influence of harmonics provided by the embodiment of the present invention;

[0049] Figure 5 A distribution diagram of overheating of the reactor coil encapsulation insulation under the influence of harmonics provided in an embodiment of the present invention;

[0050] Figure 6 A diagram of the air temperature distribution of the reactor airway under the influence of harmonics provided in an embodiment of the present invention;

[0051] Figure 7A block diagram of a device for analyzing temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics provided by an embodiment of the present invention;

[0052] Figure 8 A block diagram of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions 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 embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] See also Figure 1 This embodiment provides a method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics, comprising the following steps:

[0055] S1: obtaining simulation boundary conditions of the reactor simulation model; the reactor simulation model includes a reactor structure physical model and a reactor structure mathematical model, the reactor structure physical model is used to generate structural parameters required for calculation, and the reactor structure mathematical model is used to calculate the temperature distribution of the reactor according to the structural parameters.

[0056] It should be noted that the simulation boundary conditions include but are not limited to the working environment temperature of the reactor, the externally applied voltage and current, the properties of the cooling medium, etc. These conditions are the basis of the simulation calculation and determine the validity and accuracy of the simulation results.

[0057] The reactor structure physical model is a detailed geometric model that includes all the physical details of the reactor, such as the arrangement of the coils, the thickness of the insulation material, the design of the cooling channel, etc. These details determine the thermal and electromagnetic properties of the reactor.

[0058] The mathematical model of the reactor structure is based on the physical model and is abstracted through mathematical formulas and algorithms to facilitate numerical calculations by computers. This model includes not only geometric parameters, but also material properties (such as thermal conductivity), current distribution, magnetic field distribution, etc.

[0059] S2: Based on the simulation boundary conditions, the reactor simulation model is simulated and calculated under the harmonic voltages of different frequencies to obtain the reactor temperature distribution under the influence of harmonics of different frequencies.

[0060] It should be noted that in this step, different harmonic voltages (AC voltages with different frequency components) are applied to the reactor simulation model, and the response of the reactor under various working conditions is simulated by numerical calculation methods, so as to obtain the influence of different frequency harmonics on the temperature distribution inside the reactor.

[0061] S3: Perform temperature rise analysis of the reactor based on the reactor temperature distribution at different frequencies.

[0062] It should be noted that by comparing and analyzing the reactor temperature distribution diagrams obtained at different frequencies, it is possible to identify which frequency harmonics will cause significant temperature rise, and then determine whether the reactor can work safely and stably in the expected harmonic environment. In addition, such analysis can also help optimize the design of the reactor, reduce unnecessary temperature rise, extend equipment life and improve efficiency.

[0063] This embodiment provides a method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics. By establishing a simulation model of a dry-type air-core reactor and setting corresponding boundary conditions, simulation calculations are performed under harmonic voltages of different frequencies, thereby accurately analyzing the temperature rise effect of the reactor and improving the accuracy and reliability of thermal performance evaluation of the reactor in a high-frequency harmonic environment. This method and device can more accurately predict the temperature rise of the reactor in actual operation, which is helpful for optimizing the design and improving the safety of operation.

[0064] The following introduces other embodiments of the present invention by taking the dry-type air-core series reactor in a 35kV high-voltage parallel capacitor bank as the object of action.

[0065] The reactor body height is 694.8mm, and the package wire diameters of parallel coils 1, 2 and 3 are 3mm, 3.15mm and 3.5mm respectively. The nameplate parameters are shown in Table 1.

[0066] Table 1 Reactor nameplate parameter table

[0067]

[0068] The reactor body of this type is mainly composed of coaxial cylinder type package, insulating support bar, star bracket and other parts, such as Figure 2 As shown. The reactor is designed with 3 sets of envelopes. Each set of envelopes is made of four layers of aluminum wires wrapped with polyester film, which are spirally wound from the inside to the outside, and finally encapsulated by epoxy resin long glass fiber with insulating properties. The four layers of coils have the same inner diameter and are in parallel in electrical structure. The envelopes are separated by insulating struts, which can be used as heat dissipation channels. The upper and lower star frames of the reactor are the inlet and outlet ports of the envelope.

[0069] In one embodiment, the process of constructing a physical model of the reactor structure includes: constructing a three-dimensional model of the reactor according to the geometric parameters of the reactor; dividing different coil layers in the three-dimensional model according to the number of coil layers; utilizing the axial symmetry of the reactor to simplify the three-dimensional model into a two-dimensional model that only retains the cross-section of the coil conductor on one side; connecting the turns of each layer of the coil in series to obtain a single-layer coil winding; dividing the single-layer coil winding into an encapsulated winding to obtain a two-dimensional simulation model with turns as the basic simulation unit.

[0070] For the aforementioned dry-type hollow series reactor, the number of wire turns is used as the basic simulation unit of the reactor. Considering that the reactor has good axial symmetry, when modeling, it is only necessary to focus on the cross-section of the coil wire on one side of the reactor, and connect the wire turns contained in each layer in series to obtain a single-layer coil winding. After dividing the coil layer winding into an encapsulated winding, the two-dimensional simulation model of the reactor with wire turns as the unit is obtained, as shown in Figure 3 shown.

[0071] In one embodiment, the reactor structure mathematical model includes a field-circuit coupling model. Since the reactor is an axisymmetric structure, in a cylindrical coordinate system, the magnetic potential has only a circumferential component. AC voltage is passed through both sides of each layer of the reactor winding, and the magnetic field in the field-circuit coupling solution area follows the Maxwell equations, and the Poisson equation is satisfied at the same time, as shown in formula (1).

[0072]

[0073] In the formula, A θ is the circumferential component of the vector magnetic potential A; θ, z, r represent the angle, axial coordinate and radius in the cylindrical coordinate system respectively; μ is the magnetic permeability of the aluminum wire; J θ is the current density flowing through each layer of winding;

[0074] The circuit equation satisfied by the i-th layer winding is as follows:

[0075]

[0076] Where U i ,I i and R i is the voltage, current and resistance of the i-th winding, φ i , A i N is the flux linkage and magnetic potential of each layer of winding; i is the number of turns of the i-th coil.

[0077] In this embodiment, the role of the field-circuit coupling model is to comprehensively consider the interaction between the electromagnetic field and the circuit in the reactor temperature rise analysis to accurately predict the temperature rise of the reactor during operation. This model is crucial for evaluating the thermal performance of the reactor because it can capture the process of converting electromagnetic losses into heat and propagate this heat through heat conduction, convection, radiation, etc.

[0078] In one embodiment, the reactor structure mathematical model also includes a flow-heat coupling model, which includes a three-dimensional steady-state heat conduction equation of the reactor. The three-dimensional steady-state heat conduction equation of the reactor with the loss of each layer of winding as the internal heat source is as follows:

[0079]

[0080] In the formula, is the thermal conductivity k, specific heat c and material density The ratio of the products, that is ; is the heat source intensity F, specific heat capacity c and material density The ratio of products, ; T is the surface temperature of each layer of winding; x, y and z represent spatial coordinates; t represents time.

[0081] In a further embodiment, in the process of calculating fluid-temperature coupling, in addition to satisfying the basic heat conduction equation, the fluid control equations, namely the mass conservation equation, momentum conservation equation and energy conservation equation, should also be followed. The mass conservation equation is as follows:

[0082]

[0083] In the formula, is the air density; u, v, w are the components of the fluid velocity in the x, y, z directions.

[0084] The momentum conservation equation is as follows:

[0085]

[0086] In the formula, is the air density; u, v, w are the components of the fluid velocity in the x, y, z directions; F x 、F y 、F z is the component of body force in x, y, and z directions; and are normal stress and shear stress.

[0087] The energy conservation equation is as follows:

[0088]

[0089] Where u is the fluid velocity vector; T is the temperature; is the thermal conductivity of air; is the specific heat capacity; is the fluid temperature; S is the air viscosity dissipation term.

[0090] In one embodiment, the boundary condition setting of the fluid-heat coupling calculation includes the initial temperature setting, the fluid dynamic characteristic parameter setting, the boundary setting and the multi-physics field coupling setting. The boundary condition for the temperature rise simulation of the aforementioned dry-type air-core series reactor can be set as follows:

[0091] ① Referring to the laboratory ambient temperature, the initial temperature of the reactor and the surrounding air in the simulation is preset to 293.15K (20℃).

[0092] ② The inner diameter of the first layer of the reactor envelope is 0.477m, and the air viscosity is υ=16.96×10 -6 m 2 / s. According to the Reynolds calculation formula: Re=ud / υ, when the air flow velocity υ exceeds 0.082m / s, the Re of the inner diameter of the inner envelope of the dry air-core reactor is greater than 2300, and the air flow inside the reactor is turbulent. Therefore, the turbulence model in the unidirectional flow is selected in the fluid flow physics field for solution.

[0093] ③ The air velocity under natural convection conditions is much lower than the speed of sound and is set as incompressible flow. The cold air access plane is set at 0.125m below the dry air reactor and is set as the velocity inlet with an inlet velocity of 0.87m / s. The two sides of the air domain are open boundaries, and the upper end surface is the pressure outlet boundary with a relative pressure of zero.

[0094] ④ In multi-physics field coupling, non-isothermal flow calculations are performed, and flow heating includes viscous dissipation.

[0095] When performing fluid-heat coupling calculations, the heat transfer between the coil wires can be equivalent to a whole, and the internal heat transfer is assumed by default and the encapsulating insulation layer is retained. The total loss of the reactor coil is divided by its volume to obtain the volume heat source density of each layer of the coil, which is used as the heat source excitation of each coil to simulate the temperature of the reactor under harmonic disturbance. The results are as follows: Figure 4 As shown, (a)-(e) are the harmonic frequencies of 500Hz, 1000Hz, ... 2500Hz respectively.

[0096] Depend on Figure 4The calculation results of the reactor coil encapsulation temperature distribution under the influence of medium harmonics show that: with the increase of the harmonic voltage frequency in the system, the encapsulation of each layer of the reactor shows an upward trend. And when the harmonic frequency increases from 500Hz to 2500Hz, the temperature rise of the three layers of encapsulation exceeds the temperature rise limit of 95K standard for this type of reactor. Among them, the temperature change of the first layer of encapsulation is the most obvious, and the maximum temperature value rises to 527K, which is 229.85K higher than the initial temperature; the temperature change of the third layer of encapsulation is the smallest, and the maximum temperature rises to 436K, which is 138.85K higher than the initial temperature. It can be seen that the high-order harmonic voltage in the system will cause the reactor to overheat.

[0097] The relevant standards also stipulate the temperature of the reactor encapsulation insulation, so it is necessary to further calculate and analyze the temperature change of the reactor encapsulation insulation part. In one embodiment, the temperature rise analysis of the reactor is performed according to the reactor temperature distribution of different frequencies, and also includes: filtering the reactor coil encapsulation temperature distribution under the influence of harmonics according to the reactor encapsulation insulation temperature limit to obtain the reactor coil encapsulation insulation overheat distribution that exceeds the insulation temperature limit; based on the reactor coil encapsulation insulation overheat distribution, the reactor encapsulation insulation temperature analysis is performed.

[0098] Using the filter function in the post-processing of the finite element simulation software, set T>428.15K (155℃) to filter out Figure 4 The part of the calculated results that does not exceed the insulation temperature limit is obtained as follows Figure 5 Schematic diagram of the encapsulated insulation overheating part is shown.

[0099] Depend on Figure 5 It can be seen that the parts where the insulation is overheated and exceeds the temperature limit are distributed at the top, bottom and both sides of the enclosure 1 near the coil. And with the increase of the harmonic voltage frequency in the system, the overheating area at the top and bottom of the coil of the reactor enclosure 1 gradually expands, and the insulation temperature shows an upward trend. And when the harmonic frequency increases from 500Hz to 2500Hz, the maximum temperature of the insulation part mainly distributed near the coil side increases from 436K to 527K, exceeding the temperature limit of 428.15K (155℃) of the F-class insulation system. It can be seen that the increase in harmonic frequency in the system will also cause the insulation temperature to overheat. In addition, the overheating area and temperature at the entrance of the bottom of the enclosure at different frequencies are smaller than those at the top, which may be related to the air temperature of the air duct. In order to further analyze the differences in the overheating areas at the bottom and top, the following calculations are made: Figure 6 The airway air temperature distribution is shown.

[0100] Depend on Figure 6 From the distribution of air temperature rise in the air duct of the medium reactor, it can be seen that the air temperature in the air duct increases gradually from bottom to top under the influence of each frequency, and the temperature increases with the increase of frequency.

[0101] When the frequency increases from 500Hz to 2500Hz, the maximum temperature of the air duct increases from 352K to 389K. The temperature at the air inlet changes little and is always at the initial temperature of 293.15K. The closer the air in the air duct is to the envelope surface, the higher the temperature. The main reason for this phenomenon is that the density of the air decreases after being heated and it rises. Cold air enters from the bottom of the air duct to replace the rising hot air, resulting in a lower temperature at the bottom and a higher temperature at the top due to continuous reception of hot air. The difference in air temperature between the top and bottom of the air duct leads to uneven heat exchange of the envelope insulation, resulting in Figure 5 The phenomenon shown is that the overheated area of ​​the top insulation is large and the bottom area is small, which confirms that the size of the overheated area of ​​the bottom insulation of the reactor envelope is related to the temperature of the surrounding airway.

[0102] Based on the same inventive concept, the embodiment of the present application also provides a device for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics for realizing the above-mentioned method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in the embodiment of the device for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics provided below can be referred to the limitations of the method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics above, and will not be repeated here.

[0103] See also Figure 7 The embodiment of the present invention further provides a device for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics, comprising:

[0104] A simulation parameter acquisition module is used to obtain simulation boundary conditions of a reactor simulation model; the reactor simulation model includes a reactor structure physical model and a reactor structure mathematical model, the reactor structure physical model is used to generate structural parameters required for calculation, and the reactor structure mathematical model is used to calculate the temperature distribution of the reactor according to the structural parameters;

[0105] A simulation module is used to simulate and calculate the reactor simulation model under harmonic voltages of different frequencies based on simulation boundary conditions to obtain the reactor temperature distribution under the influence of harmonics of different frequencies;

[0106] The temperature rise analysis module is used to perform temperature rise analysis of the reactor based on the temperature distribution of the reactor at different frequencies.

[0107] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0108] Reference Figure 8 An embodiment of the present invention further provides a computer device, comprising: a memory and a processor and a computer program stored in the memory. When the computer program is executed on the processor, a method for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics as described in any one of the above methods is implemented.

[0109] The computer device may be a desktop computer, a notebook, a PDA, a cloud server or other computing device. The computer device may include, but is not limited to, a processor and a memory. Those skilled in the art will understand that Figure 8 It is only an example of a computer device and does not constitute a limitation of the computer device. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0110] The processor may be a central processing unit (CPU), 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, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0111] In some embodiments, the memory may be an internal storage unit of the computer device, such as a hard disk or memory of the computer device. In other embodiments, the memory may also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device. Further, the memory may include both an internal storage unit and an external storage device of the computer device. The memory is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program. The memory may also be used to temporarily store data that has been output or is to be output.

[0112] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics as described in any of the above methods is implemented.

[0113] In this embodiment, if the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium can at least include: any entity or device that can carry the computer program code to the camera / terminal device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. For example, USB flash drive, mobile hard disk, disk or optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0114] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0115] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0116] In the embodiments disclosed in the present application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0117] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for analyzing the temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics, characterized in that: The steps include: Acquire simulation boundary conditions of a reactor simulation model; the reactor simulation model includes a reactor structure physical model and a reactor structure mathematical model, the reactor structure physical model is used to generate structural parameters required for calculation, and the reactor structure mathematical model is used to calculate the temperature distribution of the reactor according to the structural parameters; Based on the simulation boundary conditions, the reactor simulation model is simulated and calculated under harmonic voltages of different frequencies to obtain the reactor temperature distribution under the influence of harmonics of different frequencies; The temperature rise analysis of the reactor is carried out based on the reactor temperature distribution at different frequencies.

2. The method for analyzing the temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics according to claim 1 is characterized in that: The reactor structure physical model is a two-dimensional simulation model with turns as basic simulation units, the reactor temperature distribution is the reactor coil encapsulation temperature distribution, and the construction process of the reactor structure physical model includes: Construct a three-dimensional model of the reactor according to the geometric parameters of the reactor; Dividing different coil layers in the three-dimensional model according to the number of coil layers; By utilizing the axisymmetry of the reactor, the three-dimensional model is simplified into a two-dimensional model that only retains the cross section of the coil conductor on one side; Connecting the turns of each layer of coil in series to obtain a single-layer coil winding; The single-layer coil winding is divided into encapsulated windings to obtain a two-dimensional simulation model with turns as basic simulation units.

3. The method for analyzing the temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics according to claim 2 is characterized in that: The temperature rise analysis of the reactor is carried out according to the temperature distribution of the reactor at different frequencies, and also includes: According to the reactor encapsulation insulation temperature limit, the reactor coil encapsulation temperature distribution under the influence of harmonics is filtered to obtain the reactor coil encapsulation insulation overheating distribution that exceeds the insulation temperature limit; A temperature analysis of the reactor encapsulation insulation is performed based on the reactor coil encapsulation insulation overheat distribution.

4. The method for analyzing the temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics according to claim 1 is characterized in that: The reactor structure mathematical model includes a field-circuit coupling model, and the expression of the field-circuit coupling model is as follows: The windings of each layer of coils satisfy the following formula: In the formula, A θ is the circumferential component of the vector magnetic potential A; θ, z, r represent the angle, axial coordinate and radius in the cylindrical coordinate system respectively; μ is the magnetic permeability of the aluminum wire; J θ is the current density flowing through each layer of winding; The circuit equation satisfied by the i-th layer winding is as follows: Where U i ,I i and R i is the voltage, current and resistance of the i-th winding, φ i , A i N is the flux linkage and magnetic potential of each layer of winding; i is the number of turns of the i-th coil.

5. The method for analyzing the temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics according to claim 4 is characterized in that: The reactor structure mathematical model also includes a flow-heat coupling model, and the flow-heat coupling model includes a three-dimensional steady-state heat conduction equation of the reactor. The three-dimensional steady-state heat conduction equation of the reactor is as follows: In the formula, It is the ratio of thermal conductivity to the product of specific heat capacity and material density; is the ratio of the heat source intensity to the product of specific heat capacity and material density; T is the surface temperature of each layer of winding; x, y and z represent spatial coordinates; t represents time.

6. The method for analyzing the temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics according to claim 5 is characterized in that: The fluid-heat coupling model also includes fluid control equations, which are as follows: In the formula, is the air density; u, v, w are the components of the fluid velocity in the x, y, z directions; F x 、F y 、F z is the component of body force in x, y, and z directions; and are normal stress and shear stress; u is the fluid velocity vector; T is the temperature; is the thermal conductivity of air; is the specific heat capacity; is the fluid temperature; S is the air viscosity dissipation term.

7. The method for analyzing temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics according to claim 1 is characterized in that: The setting of the simulation boundary conditions at least includes: Initial temperature setting, fluid dynamics parameter setting, boundary setting and multiphysics coupling setting.

8. A device for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics, characterized in that: include: A simulation parameter acquisition module, used to obtain simulation boundary conditions of the reactor simulation model; The reactor simulation model includes a reactor structure physical model and a reactor structure mathematical model, wherein the reactor structure physical model is used to generate structural parameters required for calculation, and the reactor structure mathematical model is used to calculate the temperature distribution of the reactor according to the structural parameters; A simulation module, used to perform simulation calculation on the reactor simulation model under harmonic voltages of different frequencies based on the simulation boundary conditions, so as to obtain the reactor temperature distribution under the influence of harmonics of different frequencies; The temperature rise analysis module is used to perform temperature rise analysis of the reactor based on the temperature distribution of the reactor at different frequencies.

9. A computer device, characterized in that: The device comprises a processor and a memory: The memory is used to store a computer program and send instructions of the computer program to the processor; The processor executes a method for analyzing temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics according to any one of claims 1 to 7 according to the instructions of the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for analyzing the temperature rise effect of a dry-type air-core reactor taking into account the influence of high-frequency harmonics according to any one of claims 1 to 7 is implemented.

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