A method and system for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor.

Abstract

A method and system for calculating the temperature distribution of the core column in an oil-immersed magnetically controlled reactor are disclosed. The method includes: establishing an overall simulation model of the core column; segmenting the core column to obtain a segmented core column; setting up a mesh for the segmented core column according to the segmentation marks and pre-simulation settings for the magnetic field of the overall model; extracting the magnetic flux density value of the core column in each segmented region; calculating the core column loss value at the corresponding position based on the magnetic flux density value of the core column in each segmented region; and using the loss values ​​at different positions of the segmented core column as load excitation for temperature field simulation calculation to obtain the actual temperature distribution on the surface of the core column. This method can effectively evaluate the temperature distribution of the core column, which helps to design the overall core structure more rationally in the early stages and avoid local overheating.

Description

Technical Field

[0001] This invention belongs to the field of magnetically controlled reactor design technology, and relates to a method and system for calculating the temperature distribution of the iron core column of an oil-immersed magnetically controlled reactor. Background Technology

[0002] With the increasing demand for reactive power compensation in power systems, traditional reactors, due to their fixed capacity, cannot track load changes. Therefore, capacity-adjustable reactors have gradually become a research hotspot. Magnetically controlled reactors, due to their advantages such as continuously adjustable output reactive power, high reliability, and simple control, are increasingly widely used in overvoltage suppression in high-voltage long-distance transmission and reactive power compensation in distribution networks.

[0003] The magnetically controlled reactor utilizes the nonlinear characteristics of the magnetization curve of the closed-loop iron core to adjust the saturation level of the closed-loop iron core by continuously adjusting the magnitude of the DC current in the DC coil on the closed-loop iron core, thereby achieving continuous adjustment of the reactance value of the AC coil on the closed-loop iron core, i.e., the reactance value of the reactance coil.

[0004] Due to the special working mode of magnetically controlled reactors, the core solenoid valve is in a saturated state for a long time. The unit mass loss of the core is much higher than that of ordinary reactors and transformers. It is very easy for local hot spots to appear at temperatures much higher than the average temperature or even overheat and burn out. Therefore, reasonable simulation calculation methods are needed to evaluate the core temperature rise during the design stage.

[0005] In the existing technology There are very few calculations specifically for the core column temperature of oil-immersed magnetically controlled reactors. The solution involves a method that, due to the presence of an air gap solenoid valve, controls the magnetic saturation of certain sections of the core, making accurate calculation of the magnetic flux density a challenge; consequently, accurate calculation of losses in different parts of the core also becomes difficult. Meanwhile, The formulas for calculating magnetic flux density and loss are mostly general formulas. For "magnetic valve" type iron cores, it is not possible to accurately calculate the magnetic flux density in the saturated and unsaturated regions, as well as the magnetic flux density and losses at the magnetic valve. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method and system for calculating the temperature distribution of the core column in an oil-immersed magnetically controlled reactor. This method effectively assesses the temperature distribution of the core column, facilitating a more rational initial design of the overall core structure and preventing localized overheating. By obtaining the temperature rise distribution in each region of the core, areas with excessively high temperature rises can be redesigned or have their magnetic circuit dimensions optimized based on simulation results. For areas with excessively low temperature rises, the temperature rise can be appropriately increased to make necessary concessions for the overall core structure. This optimization process has practical value for product design, core material selection, rational design of the "air gap magnetic valve," and optimization of the structural design to prevent localized overheating of the core.

[0007] The present invention adopts the following technical solution.

[0008] A method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor, wherein the core column includes an air gap solenoid valve, the air gap solenoid valve connecting a large cross-sectional area section and a small cross-sectional area section of silicon steel sheets; the method includes the following steps:

[0009] Step 1: Establish an overall simulation calculation model of the core column according to the actual size of the core column of the oil-immersed magnetically controlled reactor. Based on the simulation calculation model, mark the core column into segments according to the distribution of the air gap magnetic valve and the size of the silicon steel sheet to obtain a segmented core column.

[0010] Step 2: Set up the mesh for the segmented iron core column according to the segmentation mark and set up the overall model before magnetic field simulation. Extract the magnetic flux density value of the iron core column in each segment region through magnetic field simulation calculation.

[0011] Step 3: Calculate the core column loss value at the corresponding position based on the magnetic flux density value of the core column in each segmented region. Use the loss value at different positions of the segmented core column as a load excitation to perform temperature field simulation calculation and obtain the actual temperature distribution on the surface of the core column.

[0012] Preferably, the reactor core adopts a three-phase six-core column structure, the reactor core magnetic circuit is completely symmetrical, and the AC and DC magnetic circuits are separated, with the AC yoke and DC yoke connected by a connecting yoke.

[0013] Preferably, there are multiple air gap solenoid valves on each core column, and the shape, size and number of each air gap solenoid valve can be the same or different.

[0014] Preferably, the air gap solenoid valves are staggered in each stage of the iron core laminations, and the small cross-sectional area silicon steel sheets are filled with epoxy glass cloth boards, and the adjacent sides of the insulating plate are both continuous silicon steel sheets.

[0015] Preferably, in step 1, when marking the core column into segments, the segments are marked according to the size of the silicon steel sheets in the large and small cross-sectional areas. The positions between two adjacent solenoid valves are marked as a whole, and the positions of the solenoid valves without air gaps at the upper and lower ends of the core column are marked as a whole.

[0016] Preferably, in step 2, the magnetic field simulation preprocessing settings include setting material properties, excitation settings, boundary settings, computational grid and accuracy settings, iteration rate settings, error control interval and convergence settings, and different magnetic property curves are set for the large cross-sectional area segment and the small cross-sectional area segment of silicon steel sheet with segmented marking.

[0017] Preferably, in step 2, the formula for the magnetic flux density value extraction function is:

[0018]

[0019]

[0020]

[0021] Where H is the magnetic field strength;

[0022] B is the magnetic flux density;

[0023] Here is the expression for the divergence of the vector field;

[0024] Magnetic potential;

[0025] μ is the magnetic permeability;

[0026] μ0 is the vacuum permeability;

[0027] J is the volume current density;

[0028] V′ is the volume of the object being integrated;

[0029] e R Let be the unit vector pointing from the current element to the point of the field to be determined;

[0030] r′ is any spatial point where the magnetic field to be calculated is to be;

[0031] K i It is the correction coefficient obtained for the i-th segment region based on its size ratio.

[0032] Preferably, in step 3, the core loss P under AC conditions is... v and core loss P under DC bias d The calculation formula is as follows:

[0033]

[0034] Where K = K h f+K c f 2 ;

[0035] K'=K e f 1.5 ;

[0036]

[0037]

[0038]

[0039] P d =C d K h f(B m ) 2 +K c (fB m )2 +K e (fB m ) 1.5

[0040] Among them, P v Total core loss;

[0041] P h This refers to the hysteresis loss of the iron core;

[0042] P c Adding losses to the iron core;

[0043] C V The loss effect coefficient under AC sinusoidal wave conditions;

[0044] K h This is the core hysteresis loss coefficient;

[0045] K c The core eddy current loss coefficient;

[0046] K e Add a loss factor to the iron core;

[0047] B m The amplitude of the alternating magnetic flux component;

[0048] f is the frequency; I is the current element;

[0049] K and K' are K h K c K e Relationship between them;

[0050] σ is the electrical conductivity;

[0051] d is the thickness of the laminate;

[0052] f0 is the test frequency of the core curve;

[0053] C d This is the loss effect coefficient under DC bias.

[0054] Preferably, in step 3, temperature field simulation calculation is performed, and the loss values ​​at different positions of the segmented iron core column are used as load excitation. The heat dissipation, convection, radiation coefficient, oil temperature rise, and oil passage characteristic dimensions of each part of the iron core column are considered to calculate the actual temperature distribution on the surface of the iron core column.

[0055] Preferably, in step 3, the formula for calculating the actual temperature of the core column surface is:

[0056] θ m =θ ym +θ b +θ o

[0057] Where, θ m The temperature rise of the hottest spot inside the core is the actual temperature of the surface of the core column.

[0058] θ ym The temperature rise of the oil on the core surface, in K;

[0059] θ b Let K be the temperature difference between the iron core surface and the oil.

[0060] θ0 is the temperature difference between the hottest spot inside the core and the surface, in K;

[0061] Among them, natural oil circulation cooling method:

[0062] Forced oil circulation cooling method:

[0063]

[0064]

[0065] Where, q jk For the heat load per unit height of the iron core block;

[0066] K PO Add a process factor to the no-load loss;

[0067] ρ tx The density of the silicon steel sheet with iron core;

[0068] p tx This refers to the unit loss of the silicon steel sheet in the iron core;

[0069] f d This refers to the core lamination factor;

[0070] S jk This represents the gross cross-sectional area of ​​the iron core block;

[0071] f d This represents the total thickness of the core block;

[0072] b m This represents the maximum width of the core block.

[0073] m is the correction factor;

[0074] δ m This represents the thickness of the laminated sheets.

[0075] A system for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor, comprising the method described in any one of claims 1-10, including:

[0076] The model building module is used to establish an overall simulation calculation model of the core column according to the actual size of the core column of the oil-immersed magnetically controlled reactor, and to build a simulation calculation model based on the simulation calculation model.

[0077] The segmentation marking module is used to segment and mark the iron core column according to the distribution of the air gap solenoid valve and the size of the silicon steel sheet, so as to obtain a segmented iron core column.

[0078] The preprocessing module is used to set up the mesh for the segmented iron core column according to the segmentation mark and to set up the overall model before magnetic field simulation.

[0079] The magnetic flux density extraction module is used to extract the magnetic flux density value of each segment of the segmented iron core column through magnetic field simulation calculation.

[0080] The loss value calculation module is used to calculate the loss value of the core column at the corresponding position based on the magnetic flux density value of the core column in each segment region.

[0081] The temperature calculation module is used to simulate and calculate the temperature field by using the loss values ​​at different locations of the segmented iron core column as load excitation, so as to obtain the actual temperature distribution on the surface of the iron core column.

[0082] A terminal includes a processor and a storage medium; the storage medium is used to store instructions.

[0083] The processor is configured to operate according to the instructions to execute the steps of the method.

[0084] A computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method.

[0085] The beneficial effects of this invention are compared with those of the prior art:

[0086] This invention is applicable to oil-immersed magnetically controlled reactors of various specifications. It can rationally segment the core column according to the design dimensions of different air gap solenoid valves, effectively assess the temperature distribution of the core column, provide a reasonable design basis for the product, avoid local overheating, prevent failures and damage caused by excessive temperature rise, help reduce the failure rate of the product equipment, prevent serious accidents, effectively improve the safety of the equipment, and at the same time reduce the adverse effects of temperature rise on the life of the product core, so as to save operation and maintenance costs. Specifically, this invention first segments the core column, and then uses simulation technology to extract the magnetic flux density and loss of each segment using a custom function. Specifically, the core column is segmented according to the structural dimensions of the air gap solenoid valve, and each segment undergoes special mesh processing and material property settings. This allows for a more refined simulation of the core column structure. In the custom function, based on the original general formula, the structural dimensions of the air gap solenoid valve are fully considered, and a custom formula for extracting magnetic flux density and loss is added. Two parameters, a correction coefficient and a loss effect coefficient, are added. The selection of these coefficients is determined by combining the overall structural design dimensions of the core column and air gap solenoid valve. While the coefficients are not unique, they have a certain degree of matching, allowing for more accurate calculation of the magnetic flux density and loss of different parts of the core. This results in a more accurate and detailed temperature distribution calculation, which in turn feeds back into the design, strengthening weak points and making the structure more rationally optimized. Attached Figure Description

[0087] Figure 1 This is a flowchart of the calculation method of the present invention;

[0088] Figure 2 This is a schematic diagram of the overall structure of the oil-immersed magnetically controlled reactor of the present invention;

[0089] Figure 3 This is a schematic diagram of the principle of the iron core column solenoid valve of the present invention;

[0090] Figure 4 This is a side view of the iron core and connecting yoke of the present invention;

[0091] Figure 5 This is a schematic diagram of the segmented simulation calculation of the iron core column of the present invention. Detailed Implementation

[0092] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0093] Embodiment 1 of this invention provides a method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor. In a preferred but non-limiting embodiment of this invention, the core column includes an air gap magnetic valve and silicon steel sheets. The air gap magnetic valve is made of an epoxy glass cloth plate, connecting a large cross-sectional area section and a small cross-sectional area section of the silicon steel sheets. Figure 2 As shown, the oil-immersed magnetically controlled reactor core of this invention adopts a three-phase six-limb structure, with a completely symmetrical core magnetic circuit and separate AC and DC magnetic circuits. The AC yoke and DC yoke are connected by a connecting yoke. Figure 3 and Figure 4 As shown, each coil core column has several air gap solenoid valves, which are staggered. The solenoid valves are composed of silicon steel sheets with large and small cross-sectional areas connected in series, forming the core magnetic circuit. That is, the core magnetic circuit of the oil-immersed magnetically controlled reactor of the present invention is composed of large and small cross-sectional areas connected in series, and the magnetic circuit has a "valve-like" characteristic.

[0094] Among them, the large cross-sectional area section of the core is always in the unsaturated linear region.

[0095] When the small section of the iron core is fully saturated, the maximum magnetic reluctance is equivalent to the magnetic valve being completely closed.

[0096] When the small cross-section core segment is in the unsaturated linear region, the magnetic lines of force pass through it almost completely, and the magnetic valve is fully opened.

[0097] Silicon steel sheets in the saturated linear or nonlinear regions have completely different magnetization curves, resulting in completely different magnetic flux densities. The magnetic flux density value directly affects the core loss in each region, and thus affects the core temperature rise distribution.

[0098] It is understandable that the dimensions of products with different capacities and voltage levels will not be the same. It can be said that each product has a different segmentation. Therefore, the size of the large cross-sectional area segment and the small cross-sectional area segment of silicon steel sheet in this invention refers only to the relative size. The specific size is determined according to the actual product situation.

[0099] As an alternative implementation, the air gap solenoid valves are staggered in each stage of the iron core laminations, with epoxy glass cloth boards placed to fill the small cross-sectional area sections, and the adjacent sides of the insulating board are both continuous silicon steel sheets.

[0100] Each coil core column has multiple solenoid valves. The shape, size, and number of each solenoid valve may or may not be the same.

[0101] like Figure 1 As shown, the method of the present invention includes the following steps:

[0102] Step 1: Establish an overall simulation calculation model of the core column of the oil-immersed magnetically controlled reactor according to the actual size of the core column. The size of the air gap solenoid valve should be accurate and detailed. Based on the model, the core column is segmented according to the distribution of the air gap solenoid valve and the size of the silicon steel sheet to obtain a segmented core column.

[0103] Preferably, when marking the core column into segments, the segments are marked according to the size of the silicon steel sheets in the large and small cross-sectional areas. The positions between two adjacent solenoid valves are marked as a whole, and the positions of the solenoid valves without air gaps at the upper and lower ends of the core column are marked as a whole.

[0104] This step involves segmenting the core column based on the arrangement of the air gap solenoid valves. Specifically, the core column is divided into several parts according to the core dimensions with different cross-sectional areas, in order to perform detailed magnetic flux density distribution calculations and obtain segmented core loss values.

[0105] For example, such as Figure 5 As shown, the core column is segmented according to the ratio of large cross-sectional sections to small cross-sectional sections. Segments 2-4 and 6-8 are made at the locations of the solenoid valves. The positions between adjacent solenoid valves are marked as a whole. Figure 5 Position 5, at both ends of the core column, where there is no "air gap solenoid valve", can be directly marked as a whole. Figure 5 Position 1 in the middle, and so on, the entire iron core column is processed in an orderly segmented manner.

[0106] Step 2: First, set up the mesh and magnetic field simulation preprocessing for the segmented iron core column according to the segment markings. That is, set up the mesh and perform the corresponding preprocessing for the iron core column at different segment positions.

[0107] Preferably, the total number of grid cells in each segment may reach tens of thousands or hundreds of thousands, and different grid settings are implemented for each segment. For example, the length of each grid cell in a larger segment is set to 10mm, while the length of each grid cell in a smaller segment is set to 1mm or even smaller. The program will then perform the grid division work according to the settings.

[0108] The preprocessing settings for magnetic field simulation include setting material properties, excitation settings, boundary settings, computational mesh and accuracy settings, iteration rate settings, error control intervals, and convergence settings. Different magnetic characteristic curves are set for the large and small cross-sectional areas of the silicon steel sheets, which are segmented and marked. Of particular note is the need to set different magnetic characteristic curves for the large and small cross-sectional areas of the silicon steel sheets, considering the working principle and characteristics of the solenoid valve (i.e., achieving magnetic saturation control of the entire core by controlling the magnetic saturation of a portion of the core cross-section, thereby smoothly adjusting the reactor's reactance). Furthermore, special meshing is required based on the size and location of the air gap solenoid valve. These special preprocessing settings rigorously consider the magnetic saturation characteristics at different cross-sections of the core (i.e., segmented regions), and combined with the magnitude of the DC excitation current, can more accurately simulate the saturation degree of the reactor core, providing reliable data support for subsequent calculations of the magnetic field, losses, and temperature field. In short, this invention, through the setting of magnetic characteristic curves for different segmented regions, can accurately simulate and calculate the magnetic flux density value of each region of the iron core. The magnetic flux density value is the basic parameter for solving loss and temperature distribution calculations.

[0109] Secondly, the magnetic flux density value of each segment of the segmented iron core column is extracted by magnetic field simulation calculation (the magnetic flux density value of the set area is extracted by setting a function in the field calculator or by a custom function), and the core magnetic flux density value of each segment is obtained.

[0110] Preferably, the formula for the custom magnetic flux density value extraction function is:

[0111]

[0112]

[0113]

[0114] Where H is the magnetic field strength;

[0115] B is the magnetic flux density;

[0116] Here is the expression for the divergence of the vector field;

[0117] Magnetic potential;

[0118] μ is the magnetic permeability;

[0119] μ0 is the vacuum permeability;

[0120] J is the volume current density;

[0121] V′ is the volume of the object being integrated (the segmented region);

[0122] eR Let be the unit vector pointing from the current element to the point of the field to be determined;

[0123] r′ is any spatial point where the magnetic field to be calculated is to be;

[0124] K i It is the correction coefficient obtained for the i-th segment region based on its size ratio.

[0125] ∑K i The correction factor is the sum of correction factors obtained based on the different dimensions of the segmented structure.

[0126] Step 3: First, perform magnetic field loss simulation calculation: Calculate the loss value of the core column at the corresponding position based on the magnetic flux density value of the core column in each segment region, and extract the loss value of the set region through the set function or custom function in the field calculator;

[0127] This step involves simulating and calculating the core column loss value based on the specific magnetic flux density value and weight of each segment of the core column, thus obtaining the core column loss distribution.

[0128] Preferably, the core loss P under AC conditions is set according to the different magnetic characteristic curves of the segmented core. v and core loss P under DC bias d The calculation formula is as follows:

[0129] Core loss consists of two main parts: AC core loss P v and core loss P under DC bias d .

[0130] In both AC and DC conditions, the core loss consists of core hysteresis loss, eddy current loss, and additional loss.

[0131]

[0132] Where K = K h f+K c f 2 ;

[0133] K'=K e f 1.5 ;

[0134]

[0135]

[0136]

[0137] P d =C d K h f(Bm ) 2 +K c (fB m ) 2 +K e (fB m ) 1.5

[0138] Among them, P v Total core loss;

[0139] P h This refers to the hysteresis loss of the iron core;

[0140] P c Adding losses to the iron core;

[0141] C V The loss effect coefficient under AC sinusoidal wave conditions;

[0142] K h This is the core hysteresis loss coefficient;

[0143] K c The core eddy current loss coefficient;

[0144] K e Add a loss factor to the iron core;

[0145] B m The amplitude of the alternating magnetic flux component;

[0146] f is the frequency; I is the current element;

[0147] K and K' are K h K c K e Relationship between them;

[0148] σ is the electrical conductivity;

[0149] d is the thickness of the laminate;

[0150] f0 is the test frequency of the core curve;

[0151] C d This is the loss effect coefficient under DC bias.

[0152] It is particularly important to note that, taking into full account the different core saturation levels in different segment areas and the different sizes of the air gap solenoid valves selected, C V and C dThe loss effect coefficients are mutually matched. However, since the structural design dimensions of each product are not exactly the same, the two loss effect coefficients are not completely identical and are selected differently depending on the product. They are empirical coefficients, but they always maintain a matching relationship. The selection of the two loss effect coefficients makes the loss calculation of each segment area more accurate.

[0153] Then, temperature field simulation calculations are performed: The loss values ​​at different locations of the segmented core column are used as load excitations to simulate the temperature field, obtaining the actual temperature distribution on the core column surface. This step calculates the oil temperature rise of the core column based on its loss distribution and magnitude. This step uses the loss values ​​at different locations of the segmented core column as load excitations, considering heat dissipation, convection, radiation coefficient, oil temperature rise, and oil passage characteristic dimensions of each part of the core column, setting calculation parameters for each, and calculating the actual temperature distribution on the core column surface. This effectively evaluates the core column temperature distribution, providing a reasonable design basis for the product, avoiding localized overheating, and preventing malfunctions and damage caused by excessive temperature rise.

[0154] Preferably, the formula for calculating the actual temperature of the core column surface is:

[0155] The temperature of the hottest spot inside the iron core rises:

[0156] θ m =θ ym +θ b +θ o

[0157] Where, θ ym The temperature rise of the oil on the core surface, in K;

[0158] θ b Let K be the temperature difference between the iron core surface and the oil.

[0159] θ0 is the temperature difference between the hottest spot inside the core and the surface, in K.

[0160] Among them, the surface temperature rise of the iron core is:

[0161] θ bp =θ ym +θ b

[0162] Formula for calculating the temperature difference between the iron core surface and the oil:

[0163] Natural oil circulation cooling method:

[0164]

[0165] Forced oil circulation cooling method:

[0166]

[0167]

[0168] Where, q jk For the heat load per unit height of the iron core block;

[0169] K PO Add a process factor to the no-load loss;

[0170] ρ tx The density of the silicon steel sheet with iron core;

[0171] p tx The unit loss of the silicon steel sheet with iron core is W / kg;

[0172] f d This refers to the core lamination factor;

[0173] S jk The gross cross-sectional area of ​​the iron core block (cm2);

[0174] f d This represents the total thickness of the core block;

[0175] b m This represents the maximum width of the core block.

[0176] m is the correction factor;

[0177] δ m This represents the thickness of the laminated sheets.

[0178]

[0179] In practice, the ANSYS multiphysics coupling module can be used to calculate the core temperature rise. In this calculation, the excitation source can be directly coupled with the magnetic field loss calculation results. Then, the temperature field calculation is preprocessed by setting the following settings: heat dissipation, convection, and radiation coefficients of each segment of the core column, as well as calculation boundary settings, calculation accuracy settings, iteration rate settings, error control interval settings, convergence settings, etc., are set according to the oil temperature rise value and oil channel characteristic dimensions. The temperature field simulation calculation is then performed. The temperature field calculation results and the core temperature rise value are extracted. The core temperature rise and the oil temperature rise value are calculated. Based on the temperature field calculation results, the core temperature rise and the oil temperature rise value are superimposed to obtain the core temperature value.

[0180] Embodiment 2 of the present invention provides a system for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor, comprising:

[0181] The model building module is used to establish an overall simulation calculation model of the core column according to the actual size of the core column of the oil-immersed magnetically controlled reactor, and to build a simulation calculation model based on the simulation calculation model.

[0182] The segmentation marking module is used to segment and mark the iron core column according to the distribution of the air gap solenoid valve and the size of the silicon steel sheet, so as to obtain a segmented iron core column.

[0183] The preprocessing module is used to set up the mesh for the segmented iron core column according to the segmentation mark and to set up the overall model before magnetic field simulation.

[0184] The magnetic flux density extraction module is used to extract the magnetic flux density value of the iron core column in each segment region through magnetic field simulation calculation.

[0185] The loss value calculation module is used to calculate the loss value of the core column at the corresponding position based on the magnetic flux density value of the core column in each segment region.

[0186] The temperature calculation module is used to simulate and calculate the temperature field by using the loss values ​​at different locations of the segmented iron core column as load excitation, so as to obtain the actual temperature distribution on the surface of the iron core column.

[0187] A terminal includes a processor and a storage medium; the storage medium is used to store instructions.

[0188] The processor is configured to operate according to the instructions to execute the steps of the method.

[0189] A computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method.

[0190] The beneficial effects of this invention are compared with those of the prior art:

[0191] This invention is applicable to oil-immersed magnetically controlled reactors of various specifications. It can rationally segment the core column according to the design dimensions of different air gap solenoid valves, effectively assess the temperature distribution of the core column, provide a reasonable design basis for the product, avoid local overheating, prevent failures and damage caused by excessive temperature rise, help reduce the failure rate of the product equipment, prevent serious accidents, effectively improve the safety of the equipment, and at the same time reduce the adverse effects of temperature rise on the life of the product core, so as to save operation and maintenance costs.

[0192] The calculation method of this invention is applicable to oil-immersed magnetically controlled reactors of various specifications. It can perform reasonable segmentation of the core column according to the design dimensions of different air gap magnetic valves, effectively evaluate the temperature distribution of the core column, and avoid local overheating.

[0193] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0194] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0195] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0196] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0197] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor, wherein the core column includes an air gap solenoid valve, the air gap solenoid valve connecting a large cross-sectional area section and a small cross-sectional area section of silicon steel sheets; characterized in that: The calculation method includes the following steps: Step 1: Establish an overall simulation calculation model of the core column according to the actual size of the core column of the oil-immersed magnetically controlled reactor. Based on the simulation calculation model, mark the core column into segments according to the distribution of the air gap magnetic valve and the size of the silicon steel sheet to obtain a segmented core column. Step 2: Set up the mesh for the segmented iron core column according to the segmentation mark and set up the overall model before magnetic field simulation. Extract the magnetic flux density value of the iron core column in each segment region through magnetic field simulation calculation. Among them, the magnetic field simulation preprocessing settings include setting different magnetic property curves for silicon steel sheets with segmented markings for large and small cross-sectional areas; The formula for extracting magnetic flux density is: in, The magnetic field strength; Magnetic flux density; Here is the expression for the divergence of the vector field; Magnetic potential; Permeability; The vacuum permeability; Volume current density; The volume of the object being integrated; Let be the unit vector pointing from the current element to the point of the field to be determined; Let be any spatial point where the magnetic field to be calculated is located; This is the correction coefficient obtained for the i-th segment region based on its size proportion; Step 3: Calculate the core column loss value at the corresponding position based on the magnetic flux density value of the core column in each segmented region. Use the loss value at different positions of the segmented core column as a load excitation to perform temperature field simulation calculation and obtain the actual temperature distribution on the surface of the core column. Among them, the core column loss under AC is the core loss. and core loss under DC bias The calculation formula is as follows: in, ; ; ; ； ； ； in, Total core loss; This refers to the hysteresis loss of the iron core; Adding losses to the iron core; The loss effect coefficient under AC sinusoidal wave conditions; This is the core hysteresis loss coefficient; The core eddy current loss coefficient; Add a loss factor to the iron core; The amplitude of the alternating magnetic flux component; I represents frequency; I represents current element. , for , , Relationship between them; Electrical conductivity; The thickness of the laminate; The test frequency for the core curve; This is the loss effect coefficient under DC bias.

2. The method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor according to claim 1, characterized in that: The reactor core adopts a three-phase six-core column structure. The reactor core magnetic circuit is completely symmetrical, and the AC and DC magnetic circuits are separated. The AC yoke and DC yoke are connected by a connecting yoke.

3. The method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor according to claim 2, characterized in that: There are multiple air gap solenoid valves on each core column. The shape, size and number of each air gap solenoid valve can be the same or different.

4. The method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor according to claim 1, characterized in that: The air gap solenoid valves are staggered in each stage of the iron core laminations, and the small cross-sectional area silicon steel sheets are filled with epoxy glass cloth boards. The adjacent sides of the insulation board are both continuous silicon steel sheets.

5. The method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor according to claim 1, characterized in that: In step 1, when marking the core column into segments, the segments are marked according to the size of the silicon steel sheets in the large and small cross-sectional areas. The positions between two adjacent solenoid valves are marked as a whole, and the positions of the solenoid valves without air gaps at the top and bottom ends of the core column are marked as a whole.

6. The method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor according to claim 1, characterized in that: In step 2, the preprocessing settings for magnetic field simulation also include setting material properties, excitation settings, boundary settings, computational grid and accuracy settings, iteration rate settings, error control interval and convergence settings.

7. The method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor according to claim 1, characterized in that: In step 3, temperature field simulation calculations are performed. The loss values ​​at different locations of the segmented iron core column are used as load excitations. The heat dissipation, convection, radiation coefficient, oil temperature rise, and oil passage characteristic dimensions of each part of the iron core column are considered to calculate the actual temperature distribution on the surface of the iron core column.

8. The method for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor according to claim 1, characterized in that: In step 3, the formula for calculating the actual temperature of the core column surface is: in, The temperature rise of the hottest spot inside the core is the actual temperature of the surface of the core column. The temperature rise of the oil on the core surface, in K; Let K be the temperature difference between the iron core surface and the oil. The temperature difference between the hottest spot inside the core and its surface, in K; Among them, natural oil circulation cooling method: Forced oil circulation cooling method: ; in, For the heat load per unit height of the iron core block; Add a process factor to the no-load loss; The density of the silicon steel sheet with iron core; This refers to the unit loss of the silicon steel sheet in the iron core; This refers to the lamination factor of the iron core; This represents the gross cross-sectional area of ​​the iron core block; This represents the total thickness of the core block; ； ； This represents the thickness of the laminated sheets.

9. A system for calculating the temperature distribution of the core column of an oil-immersed magnetically controlled reactor, operating the method described in any one of claims 1-8, characterized in that: The system includes: The model building module is used to establish an overall simulation calculation model of the core column according to the actual size of the core column of the oil-immersed magnetically controlled reactor, and to build a simulation calculation model based on the simulation calculation model. The segmentation marking module is used to segment and mark the iron core column according to the distribution of the air gap solenoid valve and the size of the silicon steel sheet, so as to obtain a segmented iron core column. The preprocessing module is used to set up the mesh for the segmented iron core column according to the segmentation mark and to set up the overall model before magnetic field simulation. The magnetic flux density extraction module is used to extract the magnetic flux density value of each segment of the segmented iron core column through magnetic field simulation calculation. The loss value calculation module is used to calculate the loss value of the core column at the corresponding position based on the magnetic flux density value of the core column in each segment region. The temperature calculation module is used to simulate and calculate the temperature field by using the loss values ​​at different locations of the segmented iron core column as load excitation, so as to obtain the actual temperature distribution on the surface of the iron core column.

10. A terminal, comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1-8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1-8.

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