Growing concern over China-dominated rare-earth supply chains is renewing interest in active-rotor electric machine technology.
BOSTON, MA, UNITED STATES, June 17, 2026 /EINPresswire.com/ — Best Electric Machine (BEM) announced today that historical research into doubly-fed electric machines may warrant renewed attention as the automotive, aerospace, industrial, and defense sectors seek alternatives to rare-earth permanent-magnet (RE-PM) motor systems while maintaining or potentially improving performance.
According to BEM, laboratory research conducted over several decades demonstrated that electric machines employing both an active stator and active rotor architecture could achieve substantially higher air-gap utilization than conventional electric machines employing an active stator and passive rotor architecture. However, practical implementation was limited by the real-time control technology available at the time.
Supply Chain Vulnerability
The renewed interest is driven in part by growing concern over supply chain concentration in rare-earth materials, the majority of which are currently processed in China. Rare-earth permanent magnets are a critical component of high-performance electric motors used in electric vehicles, wind turbines, industrial equipment, and defense applications.
The active-rotor architecture being explored by BEM eliminates the need for rare-earth permanent magnets while potentially achieving comparable or superior performance characteristics. The company’s SYNCHRO-SYM™ electric motor concept represents one approach to implementing this architecture using modern power electronics and control systems.
BEM notes that advances in power electronics, digital signal processing, and real-time control systems over recent decades have removed some of the practical barriers that previously limited active-rotor machine implementation, potentially making the technology more viable for commercial applications than it was when the foundational research was conducted.
