Performance Comparison of BLDC Machines in Flywheel Applications: Hybrid vs. Conventional Magnet Arrays

The incorporation of rare-earth magnets in permanent magnet machines significantly improves torque characteristics and power density, enabling the development of more compact and efficient electric machines. However, their high cost and limited availability pose considerable challenges, particularly in electric vehicle applications, where these magnets account for a substantial portion of production expenses.To address this issue, this study introduces a composite magnet array as a cost-effective alternative. By employing a hybrid configuration of rare-earth and ferrite magnets, manufacturing costs can be reduced while preserving essential performance attributes such as torque enhancement and minimized torque ripple. The research focuses on an external rotor brushless DC (BLDC) machine designed for flywheel applications, analyzing the magnetic field distribution in the air gap using the proposed hybrid magnet array.The performance of this configuration is evaluated through finite element analysis (FEA) and compared with conventional magnet arrangements. Key performance metrics—including torque characteristics, eddy current losses, and magnet costs—are assessed to establish an optimal balance between efficiency, performance, and cost-effectiveness.

کلیدواژه ها:

Direct current brushless machine ، eddy current losses ، Hybrid magnet array ، Torque Ripple