# COMSOL simulation of a 3D Ferrite Bar Numerical Model For Magnetic Flux

• Hasan2022
In summary: It is typically used in electric vehicle chargers. The separation distance between the coils is typically about 1 meter.

#### Hasan2022

Hi,

I am willing to simulate a 3D ferrite bar transmitter and reciever where coupling coefficient k and Bt magnetic flux density on the each side uses the finite element method for solving partial differential equations.

The Magnetic Fields module has equation (jωσ − ω2ε0εr)A + ∇ × H = Je,

which enables calculation of magnetic field distribution B = ∇ × A, where ω is the angular frequency, σ is the electrical conductivity, ε0 is the permittivity of vacuum, εr is the relative permittivity, A is the magnetic vector potential, H is the magnetic field intensity, B is the magnetic flux density, and Je is the external current density.

In my research AC/DC Module, Magnetic Fields need to used for simulation of magnetic flux density and the coupling coefficient in 3D numerical models. Coil Current Calculation, and Frequency Domain for each of the transmitter and receiver coil need to use for studies of a problem in Comsol Multiphysics.Two parameters, the coupling coefficient k and magnetic flux density on transmitter side Bt for stray magnetic fields were used in measurements. The first parameter k was used to analyze the different ferrite core geometries. The second parameter Bt was used to analyze the optimal geometries of ferrite bars in terms of magnetic shield.Two models are required in Comsol Multiphysics, where in the first model simulated self-inductance of the transmitter coil L1, mutual inductance M, and magnetic flux density Bt. With the second model it should simulated self-inductance of the receiver coil L2.Kindly see the geometry made of n = 9 ferrite bars on the transmitter side and ferrite plate on the receiver side.

Welcome to PF.

Hasan2022 said:
Kindly see the geometry made of n = 9 ferrite bars on the transmitter side and ferrite plate on the receiver side.

Wow, that's an unusual geometry! Is it part of a real device, or is it just a way to practice complicated geometries in COMSOL?

berkeman said:
Welcome to PF.
Wow, that's an unusual geometry! Is it part of a real device, or is it just a way to practice complicated geometries in COMSOL?
It is very parctical and people using in EV chargers.
I already started to simulate in comsol, need some sequences to perform.

There are many marerials in comsol and online.
I need to kind of simulation for self inductance for both receiver and transmitter coil.

Looking at the simulation for coils, I am in little bit of confusion.
1. In Global> parameter> I included the data for calculating mutual inductacnce, turns of coils, currents, coupling coefficients, magnetic fields and so on...

2. For the geometry, I have multiple task, a reference frame should be generate like a work plane. Using solid I managed to draw spiral coils, transmitters and recievers as I posted the image.I will be happy if you can tell me which things are mandatory in this simulation, take a look very close related instructions file here.

#### Attachments

• models.acdc.helmholtz_coil.pdf
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• models.acdc.spiral_inductor.pdf
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Hasan2022 said:
It is very parctical and people using in EV chargers.
Interesting. I'm still not seeing the reasons for that particular geometry -- can you post some links to the typical chargers that you are referring to? And is it meant to be a non-contact recharge of the EV with the bottom coil and ferrites below the car and the upper coil and plate inside the car? What is the typical separation distance between the coils?

I think your response wrongly directed what I intended to ask. May be I asked something to whom who already has this simulation knowledge.
berkeman said:
Interesting. I'm still not seeing the reasons for that particular geometry -- can you post some links to the typical chargers that you are referring to? And is it meant to be a non-contact recharge of the EV with the bottom coil and ferrites below the car and the upper coil and plate inside the car? What is the typical separation distance between the coils?