Design and Optimization of Magnetic Gathering Core Inductors for Background Magnetic Field Shielding

This study investigates toroidal inductor performance under background magnetic fields (BMF) and develops mitigation solutions. Finite element analysis shows radial BMF causes up to 99% inductance reduction in Mn-Zn ferrite cores. A Fast Calculation Method (FCM) is proposed, achieving <5% error with 36,500 times speedup versus FEA. The proposed Magnetic Gathering Core (MGC) design provides up to 98% flux shielding through optimized material selection under 100 mT magnetic filed. Experimental results validate the MGC's effectiveness in maintaining inductance stability under 0-100mT BMF. The work offers practical design guidelines for robust inductors in high-power applications with strong stray fields.