specogna ruben – ansys tutorial lecture 3 – magnetostatic problems 1 ansys 7.1 tutorial magneto...

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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ANSYS 7.1 TUTORIALMagneto quasi-static problems

Ruben Specogna

A.A. 2005/06

Università di UdineDipartimento DIEGM

Gruppo di Elettrotecnica

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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Eddy current problem

• A-V Formulation for Eddy current problems:

• Low frequency• Time or frequency

domain

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EXAMPLE 1

• Toroidal massive coil feeded by a current sinusoid with various frequencies (frequency domain simulation)

• We want to see the “skin effect” in the coil

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quasi-mag_esempio5.inp/PREP7/TITLE,Toroidal coil in frequency domainET,1,PLANE53 !(AIR)KEYOPT,1,1,0 !activating keypoints (by defaults are 0)KEYOPT,1,2,0KEYOPT,1,3,1 !axisymmetricKEYOPT,1,4,0KEYOPT,1,5,0KEYOPT,1,7,0

ET,2,PLANE53 !(COIL)KEYOPT,2,1,4 !source: 4 = massive coil + coupled circuitsKEYOPT,2,2,0KEYOPT,2,3,1 !axisymmetricKEYOPT,2,4,0KEYOPT,2,5,0KEYOPT,2,7,0

ET,3,INFIN110 !(INFINITY)KEYOPT,3,1,0KEYOPT,3,3,1 !axisymmetric

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Real constant & materials

*SET,r1,1e-3 !radius of the conductor wire*SET,r,3e-3 !mean radius of the coil*SET,pi,3.141592654 !pi*SET,CURR,100 !current*SET,hf,50000 !frequency f=50kHz

!defining the real constantsR,1,r1*r1*pi,,0,0 !in this case we have to define!the real constant of the area of the coil, needed to!specify the source (help plane53 to see all real !constants available)

!materials, UIMP is an alternative to MPUIMP,1,MURX, , ,1 !mur for airUIMP,2,MURX, , ,1 !mur for the coilUIMP,2,RSVX, , ,1.8e-7 !sigma of the conductor

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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Geometric modeling

CYL4,0,0,r1 !drawing the coil

AGEN,,all,,,r,,,,,1 !translate all areas along x

!(or use “wpave,r,0,0”)

!CSYS,0

rectng,0,2*r,-r,r !air rectangle

rectng,0,4*r,-2*r,2*r !inf region rectangle

AOVLAP,all

alls,all

AATT,1 !by default all areas are associated with mat 1

LSEL,S,EXT !select all external areas

ASLL,U !deselect areas that contains those lines

AATT,2 !coil material to the remaining area

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The model is complete

LSTR,7,11 !create line from kp 7 to 11

LSTR,6,10 !create line from kp 6 to 10

ALLSEL,ALL !synonym of alls,all

asbl,all,all !subtract lines form areas

alls,all

In this picture you can see

the two new lines

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Mesh of air and coil

!create component “infinito”

LSEL,S,EXT !select external lines

LSEL,U,LOC,X,0 !deselect lines on x=0

ASLL,R !select areas with the remaining lines

cm,infinito,area !group this areas into a component

!meshing the other areas (air and coil)

alls,all

CMSEL,U,INFINITO !select all less the component

ESIZE,r1/4 !dimension of the mesh

MSHAPE,0,2D !quadrangular element

MSHKEY,0 !free mesh

AMESH,All

alls,all

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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Mesh of air and coil

Air and coil are

meshed

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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Meshing the infinite region

CMSEL,S,INFINITO !select the component “infinito”LSLA,R !select all lines contained in this areas (blue lines)LSEL,U,LOC,Y,-2*r !(1) LSEL,U,LOC,Y,-r !(2) LSEL,U,LOC,Y,r !(3) LSEL,U,LOC,Y,2*r !(4) LSEL,U,LOC,X,2*r !(5) LSEL,U,LOC,X,4*r !(6) !assign a mesh size to!the 4 selected lines!(in red)

LESIZE,ALL,,,1,1,1AATT,3,,3,0

MSHAPE,0,2DMSHKEY,1 !mapped meshAMESH,All

1

2

3

4

5 6

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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Meshing the infinite region

The mesh of the

infinite region

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Coupling with circuits 1

!the source is given by a coupling with circuits

ESEL,R,MAT,,2 !select material 2 (coil)

NSLE,R !select all nodes of the coil

cm,cond,node !create a component “cond”

!for coupling I have to choose one node of the coil

!and one node of the other domains

*get,nmin,node,,num,min !select the “min label” node

alls,all

*get,nmax,node,,num,max !select the “max” of all domain!doing so we are sure that the nodes are not the same

!we create other 2 nodes external to the domain. We’ll use

!this nodes as nodes for the external circuit

N,nmax+1,-r,-r,0 !create a node with label nmax+1

N,nmax+2,-r,r,0 !create the other node (nmax+1)

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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Coupling with circuits 2

New nodes

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Coupling with circuits 3

R,2,CURR,, !create real constant (label 2) currentET,4,CIRCU124,3,0 !et 4 (kopt 3 = Independent Current Source)!one can specify the keyopt directly with et, see “help et”

TYPE,4 !element type 4

MAT,1 !air

E,nmax+1,nmax+2,nmin !create a new element circu124

R,3,, !voltage is not imposed but it’s a state variableET,5,CIRCU124,6,0 !et 5 (6 = 2D Massive Conductor Voltage Source)

TYPE,5 !element type 5

MAT,1 !air

E,nmax+1,nmax+2,nmin !new element circu124

CP,1,CURR,cond !coupling coil-current generator

CP,2,EMF,cond !coupling coil-voltage

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Coupling with circuits 4

The two generators:

1) independent

current generator

and

2) voltage

controlled

generator

coupled with

the coil nodes

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Solution

D,nmax+1,VOLT,0,0, !V=0 on one circuit nodealls,all

LSEL,S,EXT !select external linesLSEL,U,LOC,X,0 !unselect line along x=0 SFL,all,INF !on this lines apply inf conditionFINISH

/SOLU alls,allANTYPE,3 !frequency domainHARFRQ,0,hf, !harmonic response from 0 to hfNSUBST,10, !frequencies stepsKBC,1 !stepped or ramped load (1=stepped)SOLVE FINISH

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Postprocessing

|B| |J|

With “Read results” -> “By pick” you can choose different frequencies.

Specogna Ruben – ANSYS TutorialLecture 3 – Magnetostatic Problems

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EXAMPLE 2

One voltage driven coil over a receiver coil.

2d axialsymmetrical problem.

Time domain solution

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Preprocessing/PREP7 /title,Analisi del transitorioET,1,PLANE53KEYOPT,1,1,4 !coupling with circuitsKEYOPT,1,3,1ET,2,PLANE53KEYOPT,2,3,1ET,3,PLANE53KEYOPT,3,3,1

R,1,0.25,, !coil area (real constant, see help plane53)

*SET,Ra1,4 *SET,Ra2,4.5*SET,za1,11 *SET,za2,11.5 *SET,rp1,3 *SET,rp2,3.5*SET,zp1,9.5*SET,zp2,10

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Materials and geometry

UIMP,1,MURX, , ,1, !materialsUIMP,1,MGXX, , , , UIMP,1,RSVX, , ,1.8e-08, UIMP,1,PERX, , , , UIMP,2,MURX, , ,1, UIMP,2,MGXX, , , , UIMP,2,RSVX, , ,1.8e-08, UIMP,2,PERX, , , , UIMP,3,MURX, , ,1,

RECTNG,ra1,ra2,za1,za2, !geometryRECTNG,rp1,rp2,zp1,zp2, RECTNG,0,15,0,20, AOVLAP,ALL NUMCMP,AREA APLOT

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Materials and mesh

ASEL,ALL

ASEL,S,AREA,,1,0

CM,condatt,AREA

AATT,1,,1,0

ASEL,ALL

ASEL,S,AREA,,2,0

CM,condpas,AREA

AATT,2,,2,0

ASEL,ALL

CMSEL,U,condatt

CMSEL,U,condpas

CM,aria,AREA

AATT,3,,3,0

ASEL,ALLCMSEL,S,condattESIZE,0.07143ESHAPE,2AMESH,ALLCMSEL,S,condpasESIZE,0.07143ESHAPE,2AMESH,ALLCMSEL,S,ariaESIZE,2ESHAPE,0AMESH,ALL/PNUM,MAT,1

/REPLOT

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Coupling with circuits

EPLOT,ALLESEL,ALLESEL,S,MAT,,1 NSLE,SNPLOTCM,condattnode,NODE

*get,nmin,node,,num,minalls,all,all*get,nmax,node,,num,maxR,2,0,1,1,0.02,61,1RMODIF,2,15,10,1

N,nmax+1,-10,-10,0N,nmax+2,-10, 10,0N,nmax+3,-15, 0,0

ET,4,CIRCU124,4,3

TYPE,4

REAL,2

MAT,1

E,nmax+1,nmax+2,nmax+3

R,3,1,,

RMODIF,3,15,10,2

ET,5,CIRCU124,6,0

TYPE,5

REAL,3

MAT,1

E,nmax+1,nmax+2,nmin

CP,1,curr,condattnode

CP,2,emf,condattnode

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B. cond.s and solution

D,nmax+1,volt,0,0,alls,allLSEL,S,EXTDL,ALL,,ASYMLSEL,ALLalls,all,allESEL,S,MAT,,2 NSLE,SNPLOTCM,condpas,NODENPLOTCP,3,curr,condpasCP,4,emf,condpasalls,all,alleplot

/SOLUTIONANTYPE,TRANSAUTOTS,ONKBC,1TIME,1NSUBST,10,5000,5TINTP,,,,1,,OUTRES,ALL,ALLSOLVETIME,11AUTOTS,ONKBC,1NSUBST,50,500,10SOLVE

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Postprocessing

With “Read results” -> “By pick” you can choose different time instants.