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采用COMSOL软件，对平面变压器的仿真过程进行叙述，让大家了解平面变压器的仿真流程，是个很好的指导教材Solved with COMSOL Multiphysics 5.0Results and discussionThe magnetostatic analysis yields an inductance of 0. 1l mH and a dc resistance of0. 29 mQ2. Figure 2 shows the magnetic flux density norm and the electric potentialdistributionvolume: Coil potentiaL()Volume: Magnetic flux density norm (t▲0.07▲2.88×10-42.51.50.03050.01V656×107v0igure 2: Magnetic flux density norm and electric potential distribution for themagnetostatic analysisIn the static (DC) limit, the potential drop along the winding is purely resistive andcould in principle be computed separately and before the magnetic flux density iscomputed. When increasing the frequency, inductive effects start to limit the currentand skin effect makes it increasingly difficult to resolve the current distribution in thewinding. At sufficiently high frequency, the current is mainly flowing in a thin layernear the conductor surface. When increasing the frequency further. capacitive effectscome into play and current is flowing across the winding as displacement currentdensity. When going through the resonance frequency, the device goes from behavingas an inductor to become predominantly capacitive. At the self resonance, the resistivelosses peak due to the large internal currents Figure 4 shows the surface current3 MODELING OF A 3D INDUCTORSolved with COMSOL Multiphysics 5.0distribution atl MHz. Typical for high frequency the currents are displaced towardsthe edges of the conductor.freq(1)=1.0000E6_Surfaee: Surface-current density norm (A/)▲18618Q16010￥1.02Figure 3: Surface current density at I MHz (below the resonance frequency)Figure 4 shows how the resistive part of the coil impedance peaks at the resonancefrequency near 6MHz whereas Figure 5 shows how the reactive part of the coiimpedance changes sign and goes from inductive to capacitive when passing throughthe resonance4 MODELING OFA3DINDUCTORSolved with COMSOL Multiphysics 5.0Global: Lumped port impedance(Q2)d port impedance7.5G6.583275655545352510.10.20.30.40.509igure 4: Real part of the electric potential distribution5 MODELING OF A INDUCTORSolved with COMSOL Multiphysics 5.0Global: Lumped port impedance(Q2)35000Lumped port impedance200001000050000500010000-1500020000250000.10.20.30.40.50.60.70.809Figure 5: The reactive part of the coil impedance changes sign hen passing through theresonance frequency, going from inductive to capacitiveModel library path: ACDC_Module/Inductive_ Devices_and_coils/inductor 3dFrom the file menu. choose newNEWI In the new window click model wizardMODEL WIZARDI In the model wizard window click 3D2 In the Select physics tree, select AC/DC> Magnetic Fields(mf)3 Click Add4 Click StudyMODELING OF A3D NDUCTORSolved with COMSOL Multiphysics 5.05 In the Select study tree, select Preset Studies>StationaryGEOMETRYThe main geometry is imported from file. Air domains are typically not part of a CaDgeometry so they usually have to be added later. For convenience three additionaldomains have been defined in the CAd file. These are used to define a narrow feed gapwhere an excitation can be appliedport l(impl)I On the model toolbar, click Import2 In the Settings window for Import, locate the Import section3 Click Browse4 Browse to the models model library folder and double-click the filenductor 3d. mphbinSphere /(sphl)I On the Geometry toolbar, click Sphere2 In the Settings window for Sphere, locate the Size section3 In the Radius text field, type 0.2ick to expand the Layers section. In the table, enter the following settingsLayer nameThickness(m)ayer0.055 Click the Build All Objects buttonForm Union(fin)i On the Geometry toolbar, click Build AllClick the Zoom Extents button on the Graphics toolbar7 MODELING OF A 3D INDUCTORSolved with COMSOL Multiphysics 5.03 Click the Wireframe Rendering button on the Graphics toolbarThe geometry should now look as in the figure below0.1-0.10.20.0.0.1y0.0.2Next, define selections to be used when setting up materials and physics Start bdefining the domain group for the inductor winding and continue by adding otheruseful selectionsDEFINITIONSExplicitI On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Winding3 Select Domains 7,8 and 14 onlyI On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Gap3 Select domain 9 onlI On the Definitions toolbar, click Explicit8 MODELING OF A3DINDUCTORSolved with COMSOL Multiphysics 5.02 In the Settings window for Explicit, in the Label text field, type core3 Select Domain 6 onlyExplicit 4I On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type InfiniteElements3 Select Domains 1-4 and 10-13 onlyExplicit 5I On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Non-conducting3 Select Domains 1-6 and 9-13 onlyI On the Definitions toolbar, click Explicit2 In the Settings window for Explicit, in the Label text field, type Non-conductingwithout Ie3 Select Domains 5, 6, and 9 only.Infinite Element Domain /(iel)Use infinite elements to emulate an infinite open space surrounding the inductorI On the definitions toolbar click Infinite element domain2 In the Settings window for Infinite Element Domain, locate the Domain Selectionsection3 From the Selection list. choose Infinite Elements4 Locate the Geometry section From the Type list, choose SphericalNext define the material settingsADD MATERIALI On the Model toolbar, click Add Material to open the add Material window2 Go to the Add material window3 In the tree, select AC/DC>Copper.4 Click Add to Component in the window toolbar9 MODELING OF A 3D INDUCTORSolved with COMSOL Multiphysics 5.0MATERIALSCopper(mat/)I In the Model Builder window, under Component I(comp l)>Materials click Copper(matD)2 In the Settings window for Material, locate the Geometric Entity Selection section3 From the Selection list, choose windingADD MATERIALI Go to the Add Material window2 In the tree. select built-In>Air3 Click Add to Component in the window toolbarMATERIALSAir(mat2I In the Model Builder window, under Component I(comp l)>Materials click Air(mat2)2 In the Settings window for Material, locate the Geometric Entity Selection section3 From the Selection list, choose Non-conductingThe core material is not part of the material library so it is entered as a user-definedmateriaMaterial 3(mat3)I In the Model Builder window, right-click Materials and choose Blank Material2 In the Settings window for Material, in the Label text field, type Core3 Locate the geometric Entity Selection section4 From the selection list choose Core5 Locate the Material Contents section. In the table, enter the following settingsPropertName Value Unit Property groupElectrical conductivity sigma0S/IBasicRelative permittivity epsilonrBasicRelative permeability mur1e3Basic6 On the model toolbar. click Add Material to close the Add Material windowMAGNETIC FIELDS (MF)Select Domains 1-8 and 10-14 only0MODELING OF A 3D INDUCTOR
