def initial_setup(boundary, currents, **kwargs):
'''Start femm and setup problem definition and set boundary condition.'''
if kwargs.get('hide') is True:
femm.openfemm(1)
femm.main_minimize()
else:
femm.openfemm()
# newdocument(doctype)
# From manual: Creates a new preprocessor document and opens up a new
# preprocessor window. Specify doctype to be 0 for a magnetics problem, 1
# for an electrostatics problem, 2 for a heat flow problem, or 3 for a
# current flow problem. An alternative syntax for this command is
# create(doctype)
femm.newdocument(0)
# ei probdef(units,type,precision,(depth),(minangle))
# From manual: changes the problem definition. The units parameter
# specifies the units used for measuring length in the problem domain.
# Valid "units" entries are "inches", "millimeters", "centimeters", "mils",
# "meters, and "micrometers". Set problemtype to "planar" for a 2-D planar
# problem, or to "axi" for an axisymmetric problem. The precision parameter
# dictates the precision required by the solver. For example, entering
# 1.E-8 requires the RMS of the residual to be less than 10^-8. A fourth
# parameter, representing the depth of the problem in the into-thepage
# direction for 2-D planar problems, can also be specified for planar
# problems. A sixth parameter represents the minimum angle constraint sent
# to the mesh generator.
if 'frequency' in kwargs:
freq = kwargs['frequency']
else:
freq = 6.78e6
if 'precision' in kwargs:
precision = kwargs['precision']
else:
precision = 5e-9
if 'min_angle' in kwargs:
min_angle = kwargs['min_angle']
else:
min_angle = 30
femm.mi_probdef(freq, 'millimeters', 'axi', precision, 50, min_angle)
# Circuit parameters
# mi addcircprop("circuitname", i, circuittype)
# From manual: adds a new circuit property with name "circuitname" with a
# prescribed current, i. The circuittype parameter is 0 for a
# parallel-connected circuit and 1 for a series-connected circuit.
# The currents in the primary and secondary circuits are set
I1, I2 = currents
femm.mi_addcircprop('phase_prim', I1, 1)
femm.mi_addcircprop('phase_sec', I2, 1)
# Add materials properties used in the simulation
# mi addmaterial("materialname", mu x, mu y, H c, J, Cduct, Lam d,
# Phi hmax, lam fill, LamType, Phi hx, Phi hy,NStrands,WireD)
# From manual: adds a newmaterial 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.
# – J Real Applied source current density in Amps/mm2.
# – 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
# femm 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.
femm.mi_addmaterial('air', 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0)
femm.mi_addmaterial('fr4', 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0)
femm.mi_addmaterial('copper', 1, 1, 0, 0, 58, 0, 0, 0, 0, 0, 0)
femm.mi_addmaterial('polysterimide', 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0)
femm.mi_addmaterial('teflon', 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0)
femm.mi_addmaterial('silgel', 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0)
if 'material' in kwargs:
for m in kwargs['material']:
femm.mi_addmaterial(*m)
# Boundary condition
# ei makeABC(n,R,x,y,bc)
# From manual: creates a series of circular shells that emulate the
# impedance of an unbounded domain (i.e. an Improvised Asymptotic Boundary
# Condition). The n parameter contains the number of shells to be used
# (should be between 1 and 10), R is the radius of the solution domain, and
# (x,y) denotes the center of the solution domain. The bc parameter should
# be specified as 0 for a Dirichlet outer edge or 1 for a Neumann outer
# edge. If the function is called without all the parameters, the function
# makes up reasonable values for the missing parameters.
femm.mi_makeABC(7, boundary, 0, 0, 0)
def initial_setup(limite_externe, voltage_high, **kwargs):
'''Start femm and setup problem definition and set boundary condition.'''
if kwargs.get('hide') is True:
femm.openfemm(1)
femm.main_minimize()
else:
femm.openfemm()
# newdocument(doctype)
# From manual: Creates a new preprocessor document and opens up a new
# preprocessor window. Specify doctype to be 0 for a magnetics problem, 1
# for an electrostatics problem, 2 for a heat flow problem, or 3 for a
# current flow problem. An alternative syntax for this command is
# create(doctype)
femm.newdocument(1)
# ei probdef(units,type,precision,(depth),(minangle))
# From manual: changes the problem definition. The units parameter
# specifies the units used for measuring length in the problem domain.
# Valid "units" entries are "inches", "millimeters", "centimeters", "mils",
# "meters, and "micrometers". Set problemtype to "planar" for a 2-D planar
# problem, or to "axi" for an axisymmetric problem. The precision parameter
# dictates the precision required by the solver. For example, entering
# 1.E-8 requires the RMS of the residual to be less than 10^-8. A fourth
# parameter, representing the depth of the problem in the into-thepage
# direction for 2-D planar problems, can also be specified for planar
# problems. A sixth parameter represents the minimum angle constraint sent
# to the mesh generator.
if 'precision' in kwargs:
precision = kwargs['precision']
else:
precision = 1e-9
if 'min_angle' in kwargs:
min_angle = kwargs['min_angle']
else:
min_angle = 30
femm.ei_probdef('millimeters', 'axi', precision, 100, min_angle)
# Circuit parameters
# From manual: ei_addconductorprop("conductorname", Vc, qc, conductortype)
# adds a new conductor property with name "conductorname" with either a
# prescribed voltage or a prescribed total charge. Set the unused property
# to zero. The conductortype parameter is 0 for prescribed charge and 1 for
# prescribed voltage
femm.ei_addconductorprop('high', voltage_high, 0, 1)
femm.ei_addconductorprop('zero', 0, 0, 1)
# Add materials properties used in the simulation
# ei_addmaterial(’matname’, ex, ey, qv)
# From manual: adds a new material with called ’matname’ with the material
# properties:
# ex Relative permittivity in the x- or r-direction.
# ey Relative permittivity in the y- or z-direction.
# qv Volume charge density in units of C/m3
femm.ei_addmaterial('air', 1, 1, 0)
femm.ei_addmaterial('fr4', 4.4, 4.4, 0)
femm.ei_addmaterial('polysterimide', 3.5, 3.5, 0)
femm.ei_addmaterial('teflon', 2.1, 2.1, 0)
femm.ei_addmaterial('silgel', 2.7, 2.7, 0)
femm.ei_addmaterial('midel', 3.15, 3.15, 0)
if 'material' in kwargs:
for m in kwargs['material']:
femm.ei_addmaterial(*m)
# Boundary conditions
# ei makeABC(n,R,x,y,bc)
# From manual: creates a series of circular shells that emulate the
# impedance of an unbounded domain (i.e. an Improvised Asymptotic Boundary
# Condition). The n parameter contains the number of shells to be used
# (should be between 1 and 10), R is the radius of the solution domain, and
# (x,y) denotes the center of the solution domain. The bc parameter should
# be specified as 0 for a Dirichlet outer edge or 1 for a Neumann outer
# edge. If the function is called without all the parameters, the function
# makes up reasonable values for the missing parameters.
femm.ei_makeABC(7, limite_externe, 0, 0, 0)
def draw_FEMM(
output,
is_mmfr,
is_mmfs,
sym,
is_antiper,
type_calc_leakage,
is_remove_vent=False,
is_remove_slotS=False,
is_remove_slotR=False,
is_stator_linear_BH=False,
is_rotor_linear_BH=False,
kgeo_fineness=1,
kmesh_fineness=1,
user_FEMM_dict={},
path_save="FEMM_model.fem",
is_sliding_band=True,
):
"""Draws and assigns the property of the machine in FEMM
Parameters
----------
output : Output
Output object
is_mmfr : bool
1 to compute the rotor magnetomotive force / rotor
magnetic field
is_mmfs : bool
1 to compute the stator magnetomotive force/stator
magnetic field
type_calc_leakage : int
0 no leakage calculation
1 calculation using single slot
is_remove_vent : bool
True to remove the ventilation ducts in FEMM (Default value = False)
is_remove_slotS : bool
True to solve without slot effect on the Stator (Default value = False)
is_remove_slotR : bool
True to solve without slot effect on the Rotor (Default value = False)
is_stator_linear_BH: bool
1 to use linear B(H) curve according to mur_lin, 0 to use the B(H) curve
is_rotor_linear_BH: bool
1 to use linear B(H) curve according to mur_lin, 0 to use the B(H) curve
kgeo_fineness : float
global coefficient to adjust geometry fineness
in FEMM (1: default ; > 1: finner ; < 1: less fine)
kmesh_fineness : float
global coefficient to adjust mesh fineness
in FEMM (1: default ; > 1: finner ; < 1: less fine)
sym : int
the symmetry applied on the stator and the rotor (take into account antiperiodicity)
is_antiper: bool
To apply antiperiodicity boundary conditions
Returns
-------
FEMM_dict : dict
Dictionnary containing the main parameters of FEMM (including circuits and materials)
"""
# Initialization from output for readibility
BHs = output.geo.stator.BH_curve # Stator B(H) curve
BHr = output.geo.rotor.BH_curve # Rotor B(H) curve
Is = output.elec.Is # Stator currents waveforms
Ir = output.elec.Ir # Rotor currents waveforms
machine = output.simu.machine
# Modifiy the machine to match the conditions
machine = type(machine)(init_dict=machine.as_dict())
if is_remove_slotR: # Remove all slots on the rotor
lam_dict = machine.rotor.as_dict()
machine.rotor = Lamination(init_dict=lam_dict)
if is_remove_slotS: # Remove all slots on the stator
lam_dict = machine.stator.as_dict()
machine.stator = Lamination(init_dict=lam_dict)
if is_remove_vent: # Remove all ventilations
machine.rotor.axial_vent = list()
machine.stator.axial_vent = list()
# Building geometry of the (modified) stator and the rotor
surf_list = list()
lam_ext = machine.get_lamination(is_internal=False)
lam_int = machine.get_lamination(is_internal=True)
# adding Internal Lamination surface
surf_list.extend(lam_int.build_geometry(sym=sym))
# adding the Airgap surface
if is_sliding_band:
surf_list.extend(
get_sliding_band(
sym=sym,
lam_int=output.simu.machine.get_lamination(True),
lam_ext=output.simu.machine.get_lamination(False),
)
)
else:
surf_list.extend(
get_airgap_surface(
lam_int=output.simu.machine.get_lamination(True),
lam_ext=output.simu.machine.get_lamination(False),
)
)
# adding External Lamination surface
surf_list.extend(lam_ext.build_geometry(sym=sym))
# Computing parameter (element size, arcspan...) needed to define the simulation
FEMM_dict = comp_FEMM_dict(
machine, kgeo_fineness, kmesh_fineness, type_calc_leakage
)
FEMM_dict.update(user_FEMM_dict) # Overwrite some values if needed
# The package must be initialized with the openfemm command.
femm.openfemm()
# We need to create a new Magnetostatics document to work on.
femm.newdocument(0)
# Minimize the main window for faster geometry creation.
femm.main_minimize()
# defining the problem
femm.mi_probdef(0, "meters", FEMM_dict["pbtype"], FEMM_dict["precision"])
# Creation of all the materials and circuit in FEMM
prop_dict, materials, circuits = create_FEMM_materials(
machine,
surf_list,
Is,
Ir,
BHs,
BHr,
is_mmfs,
is_mmfr,
is_stator_linear_BH,
is_rotor_linear_BH,
is_eddies,
j_t0=0,
)
create_FEMM_boundary_conditions(sym=sym, is_antiper=is_antiper)
# Draw and assign all the surfaces of the machine
for surf in surf_list:
label = surf.label
# Get the correct element size and group according to the label
mesh_dict = get_mesh_param(label, FEMM_dict)
surf.draw_FEMM(
nodeprop="None",
maxseg=FEMM_dict["arcspan"], # max span of arc element in degrees
propname="None",
elementsize=mesh_dict["element_size"],
automesh=mesh_dict["automesh"],
hide=False,
group=mesh_dict["group"],
)
assign_FEMM_surface(
surf, prop_dict[label], mesh_dict, machine.rotor, machine.stator
)
femm.mi_zoomnatural() # Zoom out
femm.mi_probdef(
FEMM_dict["freqpb"],
"meters",
FEMM_dict["pbtype"],
FEMM_dict["precision"],
FEMM_dict["Lfemm"],
FEMM_dict["minangle"],
FEMM_dict["acsolver"],
)
femm.smartmesh(FEMM_dict["smart_mesh"])
femm.mi_saveas(path_save) # Save
# femm.mi_close()
FEMM_dict["materials"] = materials
FEMM_dict["circuits"] = circuits
return FEMM_dict
def draw_FEMM(
output,
is_mmfr,
is_mmfs,
sym,
is_antiper,
type_calc_leakage,
is_remove_vent=False,
is_remove_slotS=False,
is_remove_slotR=False,
type_BH_stator=0,
type_BH_rotor=0,
kgeo_fineness=1,
kmesh_fineness=1,
user_FEMM_dict={},
path_save="FEMM_model.fem",
is_sliding_band=True,
transform_list=[],
rotor_dxf=None,
stator_dxf=None,
):
"""Draws and assigns the property of the machine in FEMM
Parameters
----------
output : Output
Output object
is_mmfr : bool
1 to compute the rotor magnetomotive force / rotor
magnetic field
is_mmfs : bool
1 to compute the stator magnetomotive force/stator
magnetic field
type_calc_leakage : int
0 no leakage calculation
1 calculation using single slot
is_remove_vent : bool
True to remove the ventilation ducts in FEMM (Default value = False)
is_remove_slotS : bool
True to solve without slot effect on the Stator (Default value = False)
is_remove_slotR : bool
True to solve without slot effect on the Rotor (Default value = False)
type_BH_stator: int
2 Infinite permeability, 1 to use linear B(H) curve according to mur_lin, 0 to use the B(H) curve
type_BH_rotor: bool
2 Infinite permeability, 1 to use linear B(H) curve according to mur_lin, 0 to use the B(H) curve
kgeo_fineness : float
global coefficient to adjust geometry fineness
in FEMM (1: default ; > 1: finner ; < 1: less fine)
kmesh_fineness : float
global coefficient to adjust mesh fineness
in FEMM (1: default ; > 1: finner ; < 1: less fine)
sym : int
the symmetry applied on the stator and the rotor (take into account antiperiodicity)
is_antiper: bool
To apply antiperiodicity boundary conditions
rotor_dxf : DXFImport
To use a dxf version of the rotor instead of build_geometry
stator_dxf : DXFImport
To use a dxf version of the stator instead of build_geometry
Returns
-------
FEMM_dict : dict
Dictionnary containing the main parameters of FEMM (including circuits and materials)
"""
# Initialization from output for readibility
BHs = output.geo.stator.BH_curve # Stator B(H) curve
BHr = output.geo.rotor.BH_curve # Rotor B(H) curve
Is = output.elec.Is # Stator currents waveforms
Ir = output.elec.Ir # Rotor currents waveforms
machine = output.simu.machine
# Computing parameter (element size, arcspan...) needed to define the simulation
FEMM_dict = comp_FEMM_dict(machine, kgeo_fineness, kmesh_fineness,
type_calc_leakage)
FEMM_dict.update(user_FEMM_dict) # Overwrite some values if needed
# The package must be initialized with the openfemm command.
try:
femm.openfemm()
except Exception as e:
raise FEMMError(
"ERROR: Unable to open FEMM, please check that FEMM is correctly installed\n"
+ str(e))
# We need to create a new Magnetostatics document to work on.
femm.newdocument(0)
# Minimize the main window for faster geometry creation.
femm.main_minimize()
# defining the problem
femm.mi_probdef(0, "meters", FEMM_dict["pbtype"], FEMM_dict["precision"])
# Modifiy the machine to match the conditions
machine = type(machine)(init_dict=machine.as_dict())
if is_remove_slotR: # Remove all slots on the rotor
lam_dict = machine.rotor.as_dict()
machine.rotor = Lamination(init_dict=lam_dict)
if is_remove_slotS: # Remove all slots on the stator
lam_dict = machine.stator.as_dict()
machine.stator = Lamination(init_dict=lam_dict)
if is_remove_vent: # Remove all ventilations
machine.rotor.axial_vent = list()
machine.stator.axial_vent = list()
# Building geometry of the (modified) stator and the rotor
surf_list = list()
lam_list = machine.get_lam_list()
lam_int = lam_list[0]
lam_ext = lam_list[1]
# Adding no_mesh for shaft if needed
if lam_int.Rint > 0 and sym == 1:
surf_list.append(
Circle(point_ref=0, radius=lam_int.Rint, label="No_mesh"))
# adding the Airgap surface
if is_sliding_band:
surf_list.extend(
get_sliding_band(sym=sym, lam_int=lam_int, lam_ext=lam_ext))
else:
surf_list.extend(get_airgap_surface(lam_int=lam_int, lam_ext=lam_ext))
# adding Both laminations surfaces (or import from DXF)
if rotor_dxf is not None:
femm.mi_readdxf(rotor_dxf.file_path)
surf_list.extend(rotor_dxf.get_surfaces())
else:
surf_list.extend(machine.rotor.build_geometry(sym=sym))
if stator_dxf is not None:
femm.mi_readdxf(stator_dxf.file_path)
surf_list.extend(stator_dxf.get_surfaces())
else:
surf_list.extend(machine.stator.build_geometry(sym=sym))
# Applying user defined modifications
for transfrom in transform_list:
for surf in surf_list:
if transfrom["label"] in surf.label and transfrom[
"type"] == "rotate":
surf.rotate(transfrom["value"])
elif transfrom["label"] in surf.label and transfrom[
"type"] == "translate":
surf.translate(transfrom["value"])
# Creation of all the materials and circuit in FEMM
prop_dict, materials, circuits = create_FEMM_materials(
machine,
surf_list,
Is,
Ir,
BHs,
BHr,
is_mmfs,
is_mmfr,
type_BH_stator,
type_BH_rotor,
is_eddies,
j_t0=0,
)
create_FEMM_boundary_conditions(sym=sym, is_antiper=is_antiper)
# Draw and assign all the surfaces of the machine
for surf in surf_list:
label = surf.label
# Get the correct element size and group according to the label
surf.draw_FEMM(
nodeprop="None",
maxseg=FEMM_dict["arcspan"], # max span of arc element in degrees
propname="None",
FEMM_dict=FEMM_dict,
hide=False,
)
assign_FEMM_surface(surf, prop_dict[label], FEMM_dict, machine.rotor,
machine.stator)
# Apply BC for DXF import
if rotor_dxf is not None:
for BC in rotor_dxf.BC_list:
if BC[1] is True: # Select Arc
femm.mi_selectarcsegment(BC[0].real, BC[0].imag)
femm.mi_setarcsegmentprop(FEMM_dict["arcspan"], BC[2], False,
None)
else: # Select Line
femm.mi_selectsegment(BC[0].real, BC[0].imag)
femm.mi_setsegmentprop(BC[2], None, None, False, None)
femm.mi_clearselected()
femm.mi_zoomnatural() # Zoom out
femm.mi_probdef(
FEMM_dict["freqpb"],
"meters",
FEMM_dict["pbtype"],
FEMM_dict["precision"],
FEMM_dict["Lfemm"],
FEMM_dict["minangle"],
FEMM_dict["acsolver"],
)
femm.smartmesh(FEMM_dict["smart_mesh"])
femm.mi_saveas(path_save) # Save
# femm.mi_close()
FEMM_dict["materials"] = materials
FEMM_dict["circuits"] = circuits
return FEMM_dict