Real-time proof of concept for a hybrid magnetic bearing with improved damping and reduced control complexity

Abstract

This paper presents a novel Axial Hybrid Magnetic Bearing (AHMB) and its corresponding control approach to overcome the constraints of conventional Active Magnetic Bearings (AMB) and Passive Magnetic Bearings (PMB). The HMB architecture comprises an independent magnetic circuit for the Permanent Magnet (PM) and AMB, resulting in improved damping and reduced control complexity. A Permanent Magnet Actuator Mechanism (PMAM) and its control algorithm were developed to render the HMB system suitable for counteracting diverse loads. Real-time experiments validated the efficacy of the HMB in mitigating external disturbances. Experimental results showed that when the load was added to the AHMB system, the rotor could be regulated to its nominal position within 1.5 s by the AMB. Moreover, the control currents to the AMB coil can be effectively reduced by ≥50%. The proposed hybrid magnetic bearing has potential applications including, but not limited to, cleanroom equipment, high-speed air compressors, high-speed turbomachinery, and flywheel energy storage systems.