Examination of magnetic properties of three-phase LLC and LCL filter chokes with multi-gap nanocrystalline block cores used in power electronics

The paper presents the effect of replacing air gaps with magnetic spacers made of three different materials. For this purpose, the technology of producing prototype cores for three-phase LLC and LCL filter chokes was developed, computer simulation of the distribution of the magnetic field lines was performed, and the magnetic properties were measured. Performed simulations and measurements confirm a significant reduction in flux dispersion when the gap is replaced with a soft magnetic insert. The use of such a solution will significantly reduce or eliminate the dispersion of magnetic flux, which is the reason for the increase in power in the core, excessive heating of the core, and noise generated by the arisen vibrations.