Magnetic Gear System Analysis with Bulk Superconductor Modelling on Rotor Sections via Pulsed Field Magnetization

Abstract

Industrial developments and increasing trend on global energy demand have intensified efforts to improve efficiency across all sectors. In this respect, mechanical gear systems play a central role in applications requiring high torque density and reliability. However, conventional mechanical gears have limitations due to friction losses, low reliability under high loads, and maintenance requirements. Magnetic gears, which can replace mechanical gears, may have potential to offer a non-contact and highly durable alternative. To further increase torque density and reduce losses, recent researches have focused on integrating superconductors into magnetic gear systems. This study presents a comprehensive analysis of a magnetic gear using bulk superconductor, which is magnetized by the pulsed field magnetization technique. Finite element simulations were conducted to evaluate the relationship between torque generation and alternating current losses of the superconducting magnetic gear under various pulsating conditions. To systematically investigate these interrelated performance factors, a derivative-free optimization algorithm was implemented that enables efficient evaluation of design trade-offs in the superconducting regime. The 20/-8 gear ratio optimization yielded a peak torque increase exceeding 100 times and an average torque increase of up to 34 times. These gains significantly exceed the limited 4- to 6-fold increase in losses, confirming the high efficiency of the proposed method.