1. ANSYS 7.1 TUTORIAL Magneto quasi-static problems Ruben Specogna
A.A. 2005/06
Università di Udine
Dipartimento DIEGM
Gruppo di Elettrotecnica
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

2. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
Eddy current problem
A-V Formulation for Eddy current problems:
Low frequency
Time or frequency domain
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

3. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
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
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

4. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
quasi-mag_esempio5.inp
/PREP7
/TITLE,Toroidal coil in frequency domain
ET,1,PLANE !(AIR)
KEYOPT,1,1,0 !activating keypoints (by defaults are 0)
KEYOPT,1,2,0
KEYOPT,1,3, !axisymmetric
KEYOPT,1,4,0
KEYOPT,1,5,0
KEYOPT,1,7,0
ET,2,PLANE !(COIL)
KEYOPT,2,1, !source: 4 = massive coil + coupled circuits
KEYOPT,2,2,0
KEYOPT,2,3, !axisymmetric
KEYOPT,2,4,0
KEYOPT,2,5,0
KEYOPT,2,7,0
ET,3,INFIN !(INFINITY)
KEYOPT,3,1,0
KEYOPT,3,3, !axisymmetric
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

5. Real constant & materials
*SET,r1,1e-3 !radius of the conductor wire
*SET,r,3e-3 !mean radius of the coil
*SET,pi, !pi
*SET,CURR, !current
*SET,hf, !frequency f=50kHz
!defining the real constants
R,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 MP
UIMP,1,MURX, , , !mur for air
UIMP,2,MURX, , , !mur for the coil
UIMP,2,RSVX, , ,1.8e-7 !sigma of the conductor
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

6. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
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
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

7. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
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
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

8. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
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/ !dimension of the mesh
MSHAPE,0,2D !quadrangular element
MSHKEY, !free mesh
AMESH,All
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

9. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
Mesh of air and coil
Air and coil are
meshed
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

10. 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,,,1,1,1
AATT,3,,3,0
MSHAPE,0,2D
MSHKEY,1 !mapped mesh
AMESH,All 4 3 5 6 2 1
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

11. Meshing the infinite region
The mesh of the
infinite region
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

12. 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 Tutorial Lecture 3 – Magnetostatic Problems

13. Coupling with circuits 2
New nodes
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

14. Coupling with circuits 3
R,2,CURR,, !create real constant (label 2) current
ET,4,CIRCU124,3,0 !et 4 (kopt 3 = Independent Current Source)
!one can specify the keyopt directly with et, see “help et”
TYPE, !element type 4
MAT, !air
E,nmax+1,nmax+2,nmin !create a new element circu124
R,3,, !voltage is not imposed but it’s a state variable
ET,5,CIRCU124,6,0 !et 5 (6 = 2D Massive Conductor Voltage Source)
TYPE, !element type 5
E,nmax+1,nmax+2,nmin !new element circu124
CP,1,CURR,cond !coupling coil-current generator
CP,2,EMF,cond !coupling coil-voltage
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

15. Coupling with circuits 4
The two generators:
1) independent
current generator
and
2) voltage
controlled
generator
coupled with
the coil nodes
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

16. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
Solution
D,nmax+1,VOLT,0,0, !V=0 on one circuit node
alls,all
LSEL,S,EXT !select external lines
LSEL,U,LOC,X,0 !unselect line along x=0
SFL,all,INF !on this lines apply inf condition
FINISH
/SOLU
ANTYPE,3 !frequency domain
HARFRQ,0,hf, !harmonic response from 0 to hf
NSUBST,10, !frequencies steps
KBC,1 !stepped or ramped load (1=stepped)
SOLVE
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

17. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
Postprocessing
|B|
|J|
With “Read results” -> “By pick” you can choose different frequencies.
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

18. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
EXAMPLE 2
One voltage driven coil over a receiver coil.
2d axialsymmetrical problem.
Time domain solution
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

19. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
Preprocessing
/PREP7
/title,Analisi del transitorio
ET,1,PLANE53
KEYOPT,1,1,4 !coupling with circuits
KEYOPT,1,3,1
ET,2,PLANE53
KEYOPT,2,3,1
ET,3,PLANE53
KEYOPT,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
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

20. Materials and geometry
UIMP,1,MURX, , ,1, !materials
UIMP,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, !geometry
RECTNG,rp1,rp2,zp1,zp2,
RECTNG,0,15,0,20,
AOVLAP,ALL
NUMCMP,AREA
APLOT
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

21. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
Materials and mesh
ASEL,ALL
ASEL,S,AREA,,1,0
CM,condatt,AREA
AATT,1,,1,0
ASEL,S,AREA,,2,0
CM,condpas,AREA
AATT,2,,2,0
CMSEL,U,condatt
CMSEL,U,condpas
CM,aria,AREA
AATT,3,,3,0
ASEL,ALL
CMSEL,S,condatt
ESIZE,
ESHAPE,2
AMESH,ALL
CMSEL,S,condpas
CMSEL,S,aria
ESIZE,2
ESHAPE,0
/PNUM,MAT,1
/REPLOT
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

22. Coupling with circuits
EPLOT,ALL
ESEL,ALL
ESEL,S,MAT,,1
NSLE,S
NPLOT
CM,condattnode,NODE
*get,nmin,node,,num,min
alls,all,all
*get,nmax,node,,num,max
R,2,0,1,1,0.02,61,1
RMODIF,2,15,10,1
N,nmax+1,-10,-10,0
N,nmax+2,-10, 10,0
N,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
E,nmax+1,nmax+2,nmin
CP,1,curr,condattnode
CP,2,emf,condattnode
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

23. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
B. cond.s and solution
D,nmax+1,volt,0,0,
alls,all
LSEL,S,EXT
DL,ALL,,ASYM
LSEL,ALL
alls,all,all
ESEL,S,MAT,,2
NSLE,S
NPLOT
CM,condpas,NODE
CP,3,curr,condpas
CP,4,emf,condpas
eplot
/SOLUTION
ANTYPE,TRANS
AUTOTS,ON
KBC,1
TIME,1
NSUBST,10,5000,5
TINTP,,,,1,,
OUTRES,ALL,ALL
SOLVE
TIME,11
NSUBST,50,500,10
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems

24. Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems
Postprocessing
With “Read results” -> “By pick” you can choose different time instants.
Specogna Ruben – ANSYS Tutorial Lecture 3 – Magnetostatic Problems