def main():
n_pontos = 40
polos = 7
deg_mec = np.linspace(0, 360, n_pontos)
deg_ele = deg_mec / polos
a_flux = np.zeros(n_pontos)
b_flux = np.zeros(n_pontos)
c_flux = np.zeros(n_pontos)
print(a_flux)
for i in range(n_pontos):
femm.mi_modifyboundprop("Sliding", 11, deg_ele[i])
femm.mi_analyse()
femm.mi_loadsolution()
a_flux[i] = femm.mo_getcircuitproperties("A")[2]
b_flux[i] = femm.mo_getcircuitproperties("A")[2]
c_flux[i] = femm.mo_getcircuitproperties("A")[2]
flux_1n = np.zeros(n_pontos)
for i in range(n_pontos):
femm.mi_modifyboundprop("Sliding", 11, deg_ele[i])
femm.mi_analyse()
femm.mi_loadsolution()
femm.mo_selectblock(1.5, 8.6)
flux_1n[i] = femm.mo_blockintegral(1) / femm.mo_blockintegral(5)
femm.mo_clearblock()
ap = 10e-3 * (10.86 + 10.96) * 1e-3 * np.pi / 14
bt = flux_1n / ap / 4
def computeL0(self):
"""Compute L0
Compute the bare inductance of the coil without projectile.
"""
self.deleteProjectile()
femm.mi_refreshview()
femm.mi_analyze()
femm.mi_loadsolution()
# print(femm.mo_getcircuitproperties("Bobine"))
self.L0 = femm.mo_getcircuitproperties("Bobine")[2] / self._i0
self.resistance = femm.mo_getcircuitproperties("Bobine")[1] / self._i0
femm.mo_close()
self.drawProjectile()
def comp_FEMM_Phi_wind(qs,
Npcpp,
is_stator,
Lfemm,
L1,
sym,
is_rescale_flux=True):
"""Compute the total fluxlinkage of the winding phases
Parameters
----------
qs : int
number of phases
Npcpp : int
number of parallel circuits per phase (maximum 2p)
is_stator : bool
true if windings are stator windings
Lfemm : float
lenght of FEMM model
L1 : float
actual lenght for rescaling fluxlinkage
sym : int
symmetry factor (ie. 1 = full machine, 2 = half machine ...)
is_rescale_flux : bool
True if rescaling should be applied
Returns
-------
Phi_wind : float
fluxlinkage of the winding phases [Vs]
"""
Phi_wind = zeros((1, qs))
if is_stator:
label = "Circs"
else:
label = "Circr"
# For each phase/circuit
for q in range(qs):
PropCirc = mo_getcircuitproperties(label + str(q))
# rescaling to account for end winding flux
if is_rescale_flux:
Kphi = L1 / Lfemm
else:
Kphi = 1
# flux linkage of phase q in Wb=Vs=HA
Phi_wind[0, q] = sym * PropCirc[2] * Kphi / Npcpp
return Phi_wind
def calc_inductance(tg, currents, inductances=(None, None), **kwargs):
''' Setup of magneto-static problem in femm to calculate inductance and
resistance of planar transformer.
Args:
tg (:obj:'TransformerGeometry'): tg contains all geometry information
of the transformer.
currents (list of float): currents in the primary and secondary side
circuits on the form [I_prim, I_sec].
inductances (list of float): self-inductances of the primary and
secondary side circuits on the form [L_prim, L_sec]. Used to calculate
mutual inductance.
Returns:
(inductance, resistance): calculated self or mutual inductance and
equivalent series resistance of either primary or secondary circuit.
'''
etiquettes_dict = {} # Dictionary to store coordinates of nodes
# initialitiation of the magneto-static problem
boundary_radius = 2 * tg.radius_dielectric
initial_setup(boundary_radius, currents, **kwargs)
# draw geometry and add block labels
add_conductors(tg, etiquettes_dict)
add_pcbs(tg)
add_isolation(tg)
add_block_labels(tg, etiquettes_dict)
# mi zoomnatural()
# From manual: zooms to a “natural” view with sensible extents.
femm.mi_zoomnatural()
# Saving geometry file
femm.mi_saveas('inductance_transformer.fem')
# Meshing and analysis
# From manual: Note that it is not necessary to run mesh before performing
# an analysis, as mi_analyze() will make sure the mesh is up to date before
# running an analysis.
# mi analyze(flag)
# From manual: runs fkern to solve the problem. The flag parameter controls
# whether the fkern window is visible or minimized. For a visible window,
# either specify no value for flag or specify 0. For a minimized window,
# flag should be set to 1.
femm.mi_analyze(1)
# Post-processing
femm.mi_loadsolution()
# mo_seteditmode(mode)
# From manual: Sets themode of the postprocessor to point, contour, or area
# mode. Valid entries for mode are "point", "contour", and "area".
femm.mo_seteditmode('area')
# mo_blockintegral(type)
# From manual: Calculate a block integral for the selected blocks
# Type Definition
# 0 A · J
# 1 A
# 2 Magnetic field energy
# 3 Hysteresis and/or lamination losses
# 4 Resistive losses
# 5 Block cross-section area
# 6 Total losses
# 7 Total current
# 8 Integral of Bx (or Br) over block
# 9 Integral of By (or rBz) over block
# 10 Block volume
# ...
# mo_getcircuitproperties("circuit")
# From manual: Used primarily to obtain impedance information associated
# with circuit properties. Properties are returned for the circuit property
# named "circuit". Three values are returned by the function. In order,
# these results are:
# – current Current carried by the circuit
# – volts Voltage drop across the circuit
# – flux_re Circuit’s flux linkage
# mo_groupselectblock(n)
# From manual: Selects all the blocks that are labeled by block labels
# that are members of group n. If no number is specified (i.e.
# mo_groupselectblock() ), all blocks are selected.
# Calculate the inductance of the circuit with non-zero current. If both
# currents are given, we calculate the mutual inductance.
L1, L2 = inductances
if (currents[0] > 0) and (currents[1] == 0):
circ = femm.mo_getcircuitproperties('phase_prim')
resistance = circ[1].real
inductance = abs(circ[2] / circ[0])
elif (currents[0] == 0) and (currents[1] > 0):
circ = femm.mo_getcircuitproperties('phase_sec')
resistance = circ[1].real
inductance = abs(circ[2] / circ[0])
else:
femm.mo_groupselectblock()
# axisymmetric problem, integral is multiplied by 2
Wm = femm.mo_blockintegral(2) * 2
inductance = ((Wm - 0.5 *
(L1 * currents[1]**2 + L2 * currents[0]**2)) /
(currents[0] * currents[1]))
resistance = 0
femm.mo_clearblock()
if kwargs.get('close') is True:
femm.closefemm()
return (inductance, resistance)
# Now,analyze the problem and load the solution when the analysis is finished
femm.mi_analyze()
femm.mi_loadsolution()
# If we were interested in the flux density at specific positions,
# we could inquire at specific points directly:
b0=femm.mo_getb(0,0);
print('Flux density at the center of the bar is %g T' % b0[1]);
b1=femm.mo_getb(0,50);
print('Flux density at r=0,z=50 is %g T' % b1[1]);
# The program will report the terminal properties of the circuit:
# current, voltage, and flux linkage
vals = femm.mo_getcircuitproperties('icoil');
# [i, v, \[Phi]] = MOGetCircuitProperties["icoil"]
# If we were interested in inductance, it could be obtained by
# dividing flux linkage by current
L = 1000*vals[2]/vals[0];
print('The self-inductance of the coil is %g mH' % L);
# Or we could, for example, plot the results along a line using
zee=[]
bee=[]
for n in range(-100,101):
b=femm.mo_getb(0,n);
zee.append(n)
bee.append(b[1]);
def computeMuImpact(self,
mus=[5, 10, 50, 100, 500, 1000, 5000],
error=0.1):
"""Compute the impact of Mu
The model is NOT LINEAR in mu. It is hard to guess what would be the effect
of an increased suceptibility and it may highly modify the response of the coil.
However, for some configuration the error is low (typically a long coil and a small projectile).
This function provides some help to know if we can consider the model linear in Mu.
Simply provide a range of possible susceptibilities for your projectile, and an
acceptable relative error.
We do not check the whole linearity, but simply in two points selected empirically.
Therefore some care should be taken regarding the output of this helper method.
Keyword Arguments:
mus {list} -- [description] (default: {[5, 10, 50, 100, 500, 1000, 5000]})
error {number} -- [description] (default: {0.1})
"""
_mu = self.mu
res = []
test_res = []
print("Coil " + self._seed + " mus")
for mu in mus:
self.mu = mu
self.deleteProjectile()
self.drawProjectile()
femm.mi_clearselected()
femm.mi_selectgroup(1)
femm.mi_analyze()
femm.mi_loadsolution()
femm.mo_groupselectblock(1)
res.append(femm.mo_getcircuitproperties("Bobine")[2] / self._i0)
femm.mi_movetranslate2(0, self.Lb / 4, 4)
femm.mi_analyze()
femm.mi_loadsolution()
femm.mo_groupselectblock(1)
test_res.append(
femm.mo_getcircuitproperties("Bobine")[2] / self._i0)
self.mu = _mu
success = True
errors = []
for i in range(0, len(test_res)):
errors.append(
numpy.abs((res[i] / res[0]) / (test_res[i] / test_res[0]) - 1))
if errors[-1] > error:
success = False
# break
if success:
return {
'valid': True,
'mus': mus,
'mu_Lz_0': res,
'mu_Lz_1': test_res,
'errors': errors
}
else:
return {
'valid': False,
'mus': mus,
'mu_Lz_0': res,
'mu_Lz_1': test_res,
'errors': errors
}
for coil_origin in coil_origins:
coil = Rectangle(coil_origin.x, coil_origin.y, Params.D4, Params.D3)
coil.assign_material(Params.CoilMaterial, Params.Turns, 'Circuit')
# Now, the finished input geometry can be displayed.
femm.mi_zoomnatural()
# We have to give the geometry a name before we can analyze it.
femm.mi_saveas('feladat2.fem')
move_vectors = [Point(0, 0)] # do it once without moving
for previous, current in zip(Params.core_gap, Params.core_gap[1:]):
move_vectors.append(Point(0, previous - current))
forces = {}
for core_gap, move_vector in zip(Params.core_gap, move_vectors):
bottom_part.move(move_vector.x, move_vector.y)
femm.mi_analyze()
femm.mi_loadsolution()
bottom_part.select_block_for_anal()
forces[core_gap] = femm.mo_blockintegral(19) # 19 means force
(current, voltage, flux_linkage) = femm.mo_getcircuitproperties('Circuit')
inductance = flux_linkage / current
print(
f'In case of {core_gap:.1f} cm gap, force is {forces[core_gap]:.2f} N; inductance is {inductance*1000:.2f} mH'
)
femm.closefemm()
# Store vector potential at the element centroid for elements that are in PMs
A[index, m] = femm.mo_geta(float(np.real(z[m])),
float(np.imag(z[m])))
elif g[m] == GroupSummary['stator_iron_core'] \
or g[m] == GroupSummary['rotor_iron_core'] \
or g[m] == GroupSummary['coils']: # Element is on the stator or rotor iron or coils
# Store flux density at the element centroid for these elements
b_temp = femm.mo_getb(float(np.real(z[m])), float(np.imag(z[m])))
b[index, m] = b_temp[0] + 1j * b_temp[1]
# Torque, force, fluxes
torque = femm.mo_gapintegral('WholeModelSlidingBand', 0)
forces = femm.mo_gapintegral('WholeModelSlidingBand', 1)
energy = femm.mo_gapintegral('WholeModelSlidingBand', 2)
cP_Uac = femm.mo_getcircuitproperties('U-GrpAC')
cP_Vac = femm.mo_getcircuitproperties('V-GrpAC')
cP_Wac = femm.mo_getcircuitproperties('W-GrpAC')
cP_Ubd = femm.mo_getcircuitproperties('U-GrpBD')
cP_Vbd = femm.mo_getcircuitproperties('V-GrpBD')
cP_Wbd = femm.mo_getcircuitproperties('W-GrpBD')
M[index, 0] = torque
M[index, 1] = forces[0]
M[index, 2] = forces[1]
M[index, 3] = energy
M[index, 4] = cP_Uac[0]
M[index, 5] = cP_Vac[0]
M[index, 6] = cP_Wac[0]
M[index, 7] = cP_Ubd[0]
M[index, 8] = cP_Vbd[0]
M[index, 9] = cP_Wbd[0]