A method and related device for analyzing the temperature rise effect of dry-type air-core reactor considering the influence of high-frequency harmonics

Abstract

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. The method includes establishing a simulation model of the reactor and its boundary conditions, and the model is divided into a physical model and a mathematical model. The physical model generates the structural parameters required for the calculation, and the mathematical model calculates the temperature distribution of the reactor based on these parameters. Based on the set boundary conditions, the simulation model is calculated under harmonic voltages of different frequencies to obtain the temperature distribution of the reactor at different frequencies, and a temperature rise analysis is performed accordingly. Through this method, the temperature rise effect of the reactor in a high-frequency harmonic environment can be accurately evaluated, and the accuracy and reliability of the thermal performance evaluation can be improved, thereby more accurately predicting the temperature rise of the reactor in actual operation, which helps to optimize the design and improve operational safety.

Description

Technical Field

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

[0002] With the global energy transition, new clean energy sources such as solar, wind, and tidal power have gained widespread adoption. These clean energy sources are often connected to power systems through nonlinear devices, significantly increasing the content of high-order harmonics (over the 20th harmonic). This not only increases the complexity of power systems but also poses new challenges to their stability and reliability, particularly in controlling harmonic power across a wide frequency range (approximately 3rd to 50th harmonics).

[0003] As a crucial component of power systems, dry-type air-core reactors shoulder the crucial tasks of compensating reactive power, limiting short-circuit current, and filtering harmonics. However, with the increasing presence of higher-order harmonics in power systems, reactors face a more challenging operating environment. To ensure safe and stable power system operation, reactors must maintain excellent performance under high-order harmonic conditions, placing higher demands on reactor design and technology.

[0004] While various methods are currently available for reactor design and analysis, research into the temperature rise effects of reactors in high-harmonic environments remains inadequate. Existing technologies often overlook the impact of high-harmonics on reactor temperature distribution and lack effective simulation methods to accurately predict reactor temperature rise under high-harmonic conditions. Furthermore, existing analysis methods struggle to fully reflect the thermal behavior of reactors in actual operation, limiting their application 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 dry-type air-core reactors taking into account the influence of high-frequency harmonics. By simulating and analyzing the field-loop and flow-heat coupling characteristics of dry-type air-core reactors, 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 impact of high-order harmonic voltage on the package temperature of the reactor, thereby improving the design level and operational 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 taking into account the influence of high-frequency harmonics, comprising the following steps:

[0008] Acquire 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 based on the structural parameters;

[0009] Based on the simulation boundary conditions, the reactor simulation model is simulated and calculated under the harmonic voltage 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 performed 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 turns as the basic simulation unit. 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 the coil layers into different layers in the 3D model according to the number of coil layers;

[0014] 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.

[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 the basic simulation unit.

[0017] Furthermore, the temperature rise analysis of the reactor is performed based on the temperature distribution of the reactor at different frequencies, and further includes:

[0018] The reactor coil encapsulation temperature distribution under the influence of harmonics is filtered according to the reactor encapsulation insulation temperature limit to obtain the reactor coil encapsulation insulation overheat distribution that exceeds the insulation temperature limit;

[0019] The temperature analysis of the reactor envelope insulation is carried out based on the overheat distribution of the reactor coil envelope 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] Where A θis the circumferential component of the vector magnetic potential A; θ, z, and r represent the angle, axial coordinate, and radius in the cylindrical coordinate system, respectively; μ is the magnetic permeability of the aluminum conductor; 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 layer winding, φ i 、A i is the flux linkage and magnetic potential of each layer of winding; N i is the number of turns of the coil in layer i.

[0027] Furthermore, the mathematical model of the reactor structure also includes a flow-heat coupling model, which includes the 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] Where, 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] Where, 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 viscous 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 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 based on the structural parameters;

[0037] The simulation module is used to simulate and calculate the reactor simulation model under harmonic voltages of different frequencies based on simulation boundary conditions, and 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 reactor temperature distribution at different frequencies.

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

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

[0041] The processor executes the method for analyzing the temperature rise effect of a dry-type air-core reactor considering 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. When the computer program is executed by a processor, the method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics as in the first aspect is implemented.

[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 that takes into account the influence of high-frequency harmonics, including obtaining simulation boundary conditions for a reactor simulation model; the reactor simulation model includes a physical model of the reactor structure and a mathematical model of the reactor structure, the physical model of the reactor structure is used to generate the structural parameters required for calculation, and the mathematical model of the reactor structure is used to calculate the temperature distribution of the reactor based on 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; and the temperature rise analysis of the reactor is performed based on the temperature distribution of the reactor at different frequencies. The present invention establishes a dry-type air-core reactor simulation model and 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 helps to optimize the design and improve operational safety. 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any 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 by 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 diagram showing overheating of the reactor coil enclosure insulation under the influence of harmonics provided in an embodiment of the present invention;

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

[0051] Figure 7A block diagram of a device for analyzing the 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 purposes, 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 making 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, including the following steps:

[0055] S1: Acquire 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 based on the structural parameters.

[0056] It should be noted that the simulation boundary conditions include but are not limited to the reactor's operating environment temperature, externally applied voltage and current, and the properties of the cooling medium. 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 channels, etc. These details determine the thermal and electromagnetic characteristics of the reactor.

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

[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 this step applies different harmonic voltages (AC voltages with different frequency components) to the reactor simulation model. Through numerical calculation methods, the response of the reactor under various operating conditions is simulated to obtain the impact 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's important to note that by comparing and analyzing reactor temperature distribution diagrams obtained at different frequencies, it's possible to identify which harmonic frequencies cause significant temperature rise, and thus determine whether the reactor can operate safely and stably in the expected harmonic environment. Furthermore, this analysis helps optimize reactor design, reducing unnecessary temperature rise, extending equipment life, and improving efficiency.

[0063] This embodiment provides a method for analyzing the temperature-rise effect of dry-type air-core reactors, taking into account the influence of high-frequency harmonics. By establishing a simulation model for the dry-type air-core reactor and setting appropriate boundary conditions, simulation calculations are performed under harmonic voltages of different frequencies. This method accurately analyzes the reactor's temperature-rise effect, improving the accuracy and reliability of thermal performance assessments of the reactor in high-frequency harmonic environments. This method and apparatus can more accurately predict the reactor's temperature rise during actual operation, facilitating design optimization and improving operational safety.

[0064] The following describes other embodiments of the present invention using a dry-type hollow series reactor in a 35kV high-voltage shunt capacitor bank as an example.

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

[0066] Table 1 Reactor nameplate parameters

[0067]

[0068] The reactor body of this type is mainly composed of coaxial cylindrical enclosure, insulating support bar, star-shaped bracket and other parts, such as Figure 2 The reactor is designed with three sets of coils. Each coil consists of four layers of aluminum wire wrapped in polyester film, spirally wound from the inside out. The coils are then encapsulated with a long glass fiber filament cured with epoxy resin for insulation. The four coils have the same inner diameter and are electrically connected in parallel. The coils are separated by insulating braces, which serve as heat dissipation channels. The upper and lower star frames of the reactor serve as the cable inlet and outlet ports.

[0069] In one embodiment, the process of constructing a physical model of the reactor structure includes: constructing a three-dimensional model of the reactor based on 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 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 the good axisymmetry of the reactor, the modeling only needs to focus on the cross-section of the coil wire on one side of the reactor and connect the turns contained in each layer in series to obtain a single-layer coil winding. After dividing the coil layer winding into the encapsulated winding, the two-dimensional simulation model of the reactor with wire turns as the unit is obtained as shown below. Figure 3 shown.

[0071] In one embodiment, the mathematical model of the reactor structure includes a field-circuit coupling model. Because the reactor is an axisymmetric structure, the magnetic potential in a cylindrical coordinate system has only a circumferential component. AC voltage is applied to both sides of each layer of the reactor winding. The magnetic field in the field-circuit coupling solution region follows Maxwell's equations, and simultaneously satisfies Poisson's equation, as shown in Equation (1).

[0072]

[0073] Where A θ is the circumferential component of the vector magnetic potential A; θ, z, and r represent the angle, axial coordinate, and radius in the cylindrical coordinate system, respectively; μ is the magnetic permeability of the aluminum conductor; 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 layer winding, φ i 、A i is the flux linkage and magnetic potential of each layer of winding; N i is the number of turns of the coil in layer i.

[0077] In this embodiment, the field-circuit coupling model comprehensively considers the interaction between the electromagnetic field and the circuit in the reactor temperature rise analysis to accurately predict the reactor's temperature rise during operation. This model is crucial for evaluating the thermal performance of reactors because it captures the process by which electromagnetic losses are converted into heat and dissipated through conduction, convection, and radiation.

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

[0079]

[0080] Where, is the thermal conductivity k, specific heat capacity c and material density The ratio of 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] Where, is the air density; u, v, w are the components of the fluid velocity in the x, y, and z directions.

[0084] The momentum conservation equation is as follows:

[0085]

[0086] Where, 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 viscous dissipation term.

[0090] In one embodiment, the boundary condition settings for the fluid-heat coupling calculation include initial temperature settings, fluid dynamics parameter settings, boundary settings, and multi-physics field coupling settings. The boundary conditions 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 number calculation formula: Re = ud / υ, when the air velocity υ exceeds 0.082 m / s, the Re of the inner diameter of the dry-type air-core reactor's inner envelope is greater than 2300, and the air flow inside the reactor is turbulent. Therefore, the turbulence model for unidirectional flow is selected in the fluid flow physics field for solution.

[0093] ③ Under natural convection conditions, the air velocity is much lower than the speed of sound, setting the flow as incompressible. A cold air inlet is located 0.125 m below the dry-type air-core reactor, serving as the velocity inlet. The inlet velocity is 0.87 m / s. The two sides of the air domain are open boundaries, while the upper end serves as 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 conductors can be considered as a whole. By default, internal heat transfer is assumed and the encapsulating insulation layer is retained. The total loss of the reactor coil is divided by its volume to obtain the volumetric heat source density of each layer of coil. This is used as the heat source excitation for 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 4Calculations of the reactor coil envelope temperature distribution under the influence of medium harmonics show that as the system's harmonic voltage frequency increases, the temperature of each layer of the reactor envelope increases. Furthermore, when the harmonic frequency increases from 500Hz to 2500Hz, the temperature rise of all three layers exceeds the 95K standard temperature rise limit for this type of reactor. The temperature change is most pronounced in the first layer, with the maximum temperature increasing to 527K, a 229.85K increase relative to the initial temperature. The temperature change is smallest in the third layer, with the maximum temperature increasing to 436K, a 138.85K increase relative to the initial temperature. This indicates that the high-order harmonic voltages present in the system can cause reactor overheating.

[0097] Relevant standards also specify the temperature of the reactor's encapsulated insulation, necessitating further calculation and analysis of temperature changes in the reactor's encapsulated insulation. In one embodiment, a temperature rise analysis of the reactor is performed based on the reactor's temperature distribution at different frequencies. The analysis also includes filtering the reactor coil encapsulated insulation temperature distribution under harmonic influences based on the reactor's encapsulated insulation temperature limit to obtain an overheat distribution of the reactor coil encapsulated insulation that exceeds the insulation temperature limit; and performing a temperature analysis of the reactor's encapsulated insulation based on the overheat distribution of the reactor coil encapsulated insulation.

[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 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 of the insulation that are overheated and exceed the temperature limit are distributed in the top, bottom and both sides of the enclosure 1 near the coil area. And with the increase of the harmonic voltage frequency in the system, the range of 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 air temperature distribution in the airway is shown.

[0100] Depend on Figure 6 The distribution of air temperature rise in the air duct of the reactor shows 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 the 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 top insulation overheating area is large and the bottom area is small, which confirms that the size of the insulation overheating area at the bottom of the reactor envelope is related to the surrounding air duct temperature.

[0102] Based on the same inventive concept, an embodiment of the present application further provides a device for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics, which is used to implement the aforementioned method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics. The solution provided by this system is similar to the solution described in the aforementioned method. Therefore, the specific limitations of 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 found in 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 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 based on the structural parameters;

[0105] The simulation module is used to simulate and calculate the reactor simulation model under harmonic voltages of different frequencies based on simulation boundary conditions, and 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 reactor temperature distribution at different frequencies.

[0107] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and 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 into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into 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, and 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, it implements the temperature rise effect analysis method of the dry-type air-core reactor considering the influence of high-frequency harmonics as described in any one of the above methods.

[0109] The computer device may be a desktop computer, notebook computer, PDA, cloud server or other computing device. The computer device may include, but is not limited to, a processor and a memory. It will be understood by those skilled in the art that Figure 8 The computer device is merely an example and does not constitute a limitation on the computer device. The computer device may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device 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), 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.

[0111] In some embodiments, the memory may be an internal storage unit of the computer device, such as a hard drive 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 drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped with the computer device. Furthermore, the memory may include both an internal storage unit of the computer device and an external storage device. The memory is used to store an operating system, application programs, a boot loader, 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 about 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 considering the influence of high-frequency harmonics as described in any one of the above methods is implemented.

[0113] In this embodiment, if the integrated unit is implemented as a software functional unit and sold or used as a standalone product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application can implement all or part of the process steps in the above-mentioned method embodiments by using a computer program to instruct the relevant hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a camera / terminal device, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signals, telecommunication signals, and software distribution media. Examples include USB flash drives, removable hard drives, magnetic disks, or optical disks. In some jurisdictions, based on legislation and patent practice, computer-readable media cannot be electric carrier signals or telecommunication signals.

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

[0115] Those skilled 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 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 merely schematic. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, 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 they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. 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 various embodiments of the present invention.

Claims

1. A method for analyzing the temperature rise effect of dry-type air-core reactors considering the influence of high-frequency harmonics, characterized in that: The steps include: Acquiring 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 based on the structural parameters; Based on the simulation boundary conditions, simulation calculations are performed on the reactor simulation model under harmonic voltages of different frequencies to obtain the reactor temperature distribution under the influence of harmonics of different frequencies; Conduct temperature rise analysis of reactors based on reactor temperature distribution at different frequencies; 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. 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; Dividing the single-layer coil winding into encapsulated windings to obtain a two-dimensional simulation model with turns as basic simulation units; The reactor temperature rise analysis is performed based on the reactor temperature distribution at different frequencies, including: The reactor coil encapsulation temperature distribution under the influence of harmonics is filtered according to the reactor encapsulation insulation temperature limit to obtain the reactor coil encapsulation insulation overheat 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.

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 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: ； Where A θ is the circumferential component of the vector magnetic potential A; θ, z, and r represent the angle, axial coordinate, and radius in the cylindrical coordinate system, respectively; μ is the magnetic permeability of the aluminum conductor; 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 layer winding, 、A i is the flux linkage and magnetic potential of each layer of winding; N i is the number of turns of the coil in layer i.

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 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: ； Where, 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.

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 3 is characterized in that: The fluid-heat coupling model also includes a fluid control equation, which is as follows: ； ； ； Where, 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; 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 viscous dissipation term.

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 1, 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.

6. A device for analyzing the temperature rise effect of dry-type air-core reactors considering the influence of high-frequency harmonics, characterized in that: include: A simulation parameter acquisition module is 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 is used to perform simulation calculations on the reactor simulation model under harmonic voltages of different frequencies based on the simulation boundary conditions to obtain the reactor temperature distribution under the influence of harmonics of different frequencies; Temperature rise analysis module, used to analyze the temperature rise of the reactor based on the reactor temperature distribution at different frequencies; 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. 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; Dividing the single-layer coil winding into encapsulated windings to obtain a two-dimensional simulation model with turns as basic simulation units; The reactor temperature rise analysis is performed based on the reactor temperature distribution at different frequencies, including: The reactor coil encapsulation temperature distribution under the influence of harmonics is filtered according to the reactor encapsulation insulation temperature limit to obtain the reactor coil encapsulation insulation overheat 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.

7. A computer device, characterized in that: The device includes a processor and a memory: The memory is used to store the computer program and send instructions of the computer program to the processor; The processor executes the method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics according to any one of claims 1 to 5 according to the instructions of the computer program.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the method for analyzing the temperature rise effect of a dry-type air-core reactor considering the influence of high-frequency harmonics according to any one of claims 1 to 5.

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