In the next week I will post a series of interesting simulation findings about the shielding of magnetic fields in kHz frequencies....:
High currents flowing in the powertrain of electric vehicles create magnetic fields that can be well above regulatory limits for human body exposure. Automotive OEMS face the challenge to shield these fields, typically in the range of kHz. Simulations can help you to understand the physics behind shielding:
Conductive Shielding: An induced current creates a magnetic field of direction opposite to the source, reducing the overall field. As induced current increases with frequency, blue curve points downwards. However, there is no shielding at very low frequencies.
The magnetic field at the surface of the conductive material is tangential.
Permeable Shielding: A high permeable material changes the distribution of the magnetic field generated by the source. Simply speaking it “pushes” the field away. This effect is not frequency depended that’s why the green curve is flat.
The magnetic field at the surface of the permeable material is normal.
For a material like steel, that has a significant conductivity and permeability, both shielding types are superimposed.
The absolute values of the curves depend on shield thickness, material properties, source current, distance of source and shield and so on. But it only takes a few minutes to run these calculations.
Magnetic Field Shielding-kHz
