[Music]
welcome to this ansys innovation course
on simulating a novel multi-material inductor in ansys maxwell
In this video we will give an overview
of multi-material inductor design for power converters
A power converter consists of
semiconductor switches like IGBT or MOSFETs
to convert power from one form to another
magnetic components are necessary to store
and convert electrical and magnetic energy
they're widely used in switching power
converter devices
here are some challenges concerning
magnetics in power converters
typically magnetic components make up a
significant portion of a power converter
so it is critical to reduce the size of
the magnetic components
to design smaller power devices
for proper functionality of a converter
the inductances of magnetic components
need to be maintained while reducing
their sizes
in other words we need to increase the
inductance density
of a magnetic component
a novel way to do this is by using
different material properties
in a single core of an inductor
let's take a look at this equation
we can see that a high magnetic permeability
results in a high inductance value for
the same size of the inductor
leading to higher inductance density
however magnetic materials usually have
saturation effect
this will cause the magnetic
permeability to drop
as the dc magnetic field increases
thus lowering the overall inductance
as dc bias is applied to an inductor
Moreover
non-uniform distribution of dc field in
the core
accelerates saturation of magnetic materials
take this toroid core example
dc field is higher in inner rings
and lower in outer rings
so, material in inner rings saturates earlier
to slow the rate of saturation
we can apply
multiple magnetic materials of different
permeability responses to the H field
in this example we can use these three
materials
for the different rings in the core
since the H field varies at different rings
we can use the material with the highest permeability
for that H field range
for such a multi-material design
the overall inductance
is higher than the toroidal core with a
single material
using ampere's law we can calculate the
corresponding ring radius
at different H fields for a specific dc current
in this figure
we can see there are two critical radii
r1 and r2
for ring with radius smaller
than r1
we should use material 3 since it has
the highest permeability
in that H field range
similarly
for ring with radius greater than r2
we should use material 1
and for radius between r1 and r2
we should use material 2
A 3-material toroidal core
under a 10 amp dc current
the calculated r1 and r2
are 1.59 millimeter and 2.89 millimeter
respectively
we can set the inner radius and outer
radius of the whole toroidal core
and then compare the inductances
of the cores
for these two scenarios
in our next video we'll show how to
evaluate the inductances for the two
scenarios in ansys maxwell
thank you for watching this video
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on maxwell or any of our simulation
tools
visit our ansys learning channel
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