Comprehensive investigation on high-frequency rotational magnetic properties of core materials for high-speed motors

In this paper, the rotational magnetic properties of ultra-thin non-oriented silicon steel ST100 (200 Hz - 5 kHz) are measured by the novel two-dimensional magnetic property tester, with nanocrystalline alloy 1K107B (1 kHz - 20 kHz) serving as a reference. The anisotropy behavior of these materials under varying flux densities is analyzed based on the experimental results. The change in anisotropy under circular magnetization is explained by comparing the B-H phase difference at different flux densities and frequencies. Taking the elliptical magnetization of ST100 at 1 kHz as a case study, the magnetic properties of materials with different levels of rotational magnetization are systematically investigated. By comparing the phase difference of B-H loci and the harmonic content of H at different axial ratios and flux densities, the factors contributing to the nonlinear behavior of rotational magnetization are identified. Additionally, the variation in core loss under different rotational conditions is analyzed. It can provide theoretical and data support for the magnetic structure design and loss evaluation in the high-speed motor.