3.3.9 Object Properties

• mi addmaterial("materialname", mu x, mu y, H c, Jr, Ji, Cduct, Lam d, Phi hmax,

lam fill, LamType, Phi hx, Phi hy),NStrands,WireD adds a new material with called

"materialname" with the material properties:

– mu x Relative permeability in the x- or r-direction.

– mu y Relative permeability in the y- or z-direction.

– H c Permanent magnet coercivity in Amps/Meter.

– Jr Real (in phase) portion of the applied source current density in Amps/mm2.

– Ji Imaginary (out of phase) portion of the applied source current density in Amps/mm2.

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– Cduct Electrical conductivity of the material in MS/m.

– Lam d Lamination thickness in millimeters.

– Phi hmax Hysteresis lag angle in degrees, used for nonlinear BH curves.

– Lam fill Fraction of the volume occupied per lamination that is actually filled with

iron (Note that this parameter defaults to 1 the femme preprocessor dialog box because,

by default, iron completely fills the volume)

– Lamtype Set to

∗ 0 – Not laminated or laminated in plane

∗ 1 – laminated x or r

∗ 2 – laminated y or z

∗ 3 – Magnet wire

∗ 4 – Plain stranded wire

∗ 5 – Litz wire

∗ 6 – Square wire

– Phi hx Hysteresis lag in degrees in the x-direction for linear problems.

– Phi hy Hysteresis lag in degrees in the y-direction for linear problems.

– NStrands Number of strands in the wire build. Should be 1 for Magnet or Square wire.

– WireD Diameter of each wire constituent strand in millimeters.

Note that not all properties need be defined–properties that aren’t defined are assigned default

values.

• mi addbhpoint("blockname",b,h) Adds a B-H data point the the material specified by

the string "blockname". The point to be added has a flux density of b in units of Teslas and

a field intensity of h in units of Amps/Meter.

• mi clearbhpoints("blockname") Clears all B-H data points associatied with the material

specified by "blockname".

• mi addpointprop("pointpropname",a re,a im,j re,j im) adds a new point property

of name "pointpropname" with either a specified potential a im, a re in unitsWebers/Meter

or a point current j im, j re in units of Amps. Set the unused parameter pairs to 0.

• mi addboundprop("propname", A0, A1, A2, Phi, Mu, Sig, c0, c1, BdryFormat)

adds a new boundary property with name "propname"

– For a “Prescribed A” type boundary condition, set the A0, A1, A2 and Phi parameters

as required. Set all other parameters to zero.

– For a “Small Skin Depth” type boundary condtion, set the Mu to the desired relative

permeability and Sig to the desired conductivity in MS/m. Set BdryFormat to 1 and

all other parameters to zero.

– To obtain a “Mixed” type boundary condition, set C1 and C0 as required and BdryFormat

to 2. Set all other parameters to zero.

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– For a “Strategic dual image” boundary, set BdryFormat to 3 and set all other parameters

to zero.

– For a “Periodic” boundary condition, set BdryFormat to 4 and set all other parameters

to zero.

– For an “Anti-Perodic” boundary condition, set BdryFormat to 5 set all other parameters

to zero.

• mi addcircprop("circuitname", i re, i im, circuittype)

adds a new circuit property with name "circuitname" with a prescribed current. The

circuittype parameter is 0 for a parallel-connected circuit and 1 for a series-connected

circuit.

• mi deletematerial("materialname") deletes the material named "materialname".

• mi deleteboundprop("propname") deletes the boundary property named "propname".

• mi deletecircuit("circuitname") deletes the circuit named circuitname.

• mi deletepointprop("pointpropname") deletes the point property named "pointpropname"

• mi_modifymaterial("BlockName",propnum,value) This function allows for modification

of a material’s properties without redefining the entire material (e.g. so that current can

be modified from run to run). The material to be modified is specified by "BlockName".

The next parameter is the number of the property to be set. The last number is the value to

be applied to the specified property. The various properties that can be modified are listed

below:

propnum Symbol Description

0 BlockName Name of the material

1 μx x (or r) direction relative permeability

2 μy y (or z) direction relative permeability

3 Hc Coercivity, Amps/Meter

4 Jr Real part of current density, MA/m2

5 Ji Imaginary part of current density, MA/m2

6 Electrical conductivity, MS/m

7 dlam Lamination thickness, mm

8 hmax Hysteresis lag angle for nonlinear problems, degrees

9 LamFill Iron fill fraction

10 LamType 0 = None/In plane, 1 = parallel to x, 2=parallel to y

11 hx Hysteresis lag in x-direction for linear problems, degrees

12 hy Hysteresis lag in y-direction for linear problems, degrees

• mi_modifyboundprop("BdryName",propnum,value) This function allows for modification

of a boundary property. The BC to be modified is specified by "BdryName". The next

parameter is the number of the property to be set. The last number is the value to be applied

to the specified property. The various properties that can be modified are listed below:

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propnum Symbol Description

0 BdryName Name of boundary property

1 A0 Prescribed A parameter

2 A1 Prescribed A parameter

3 A2 Prescribed A parameter

4 Prescribed A phase

5 μ Small skin depth relative permeability

6 Small skin depth conductivity, MS/m

7 c0 Mixed BC parameter

8 c1 Mixed BC parameter

9 BdryFormat Type of boundary condition:

0 = Prescribed A

1 = Small skin depth

2 = Mixed

3 = Strategic Dual Image

4 = Periodic

5 = Antiperiodic

• mi_modifypointprop("PointName",propnum,value) This function allows for modification

of a point property. The point property to be modified is specified by "PointName".

The next parameter is the number of the property to be set. The last number is the value to

be applied to the specified property. The various properties that can be modified are listed

below:

propnum Symbol Description

0 PointName Name of the point property

1 Are Real part of nodal potential, Weber/Meter

2 Aim Imaginary part of nodal potentialWeber/Meter

3 Jre Real part of nodal current, Amps

4 Jim Imaginary part of nodal current, Amps

• mi_modifycircprop("CircName",propnum,value) This function allows for modification

of a circuit property. The circuit property to be modified is specified by "CircName".

The next parameter is the number of the property to be set. The last number is the value to

be applied to the specified property. The various properties that can be modified are listed

below:

propnum Symbol Description

0 CircName Name of the circuit property

1 ire Real part of total current

2 iim Imaginary part of total current

3 CircType 0 = Parallel, 1 = Series

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