Starting Characteristics of Axial and Radial Type Ultra-Lightweight Motors Based on Magnetic Resonance Coupling

In this paper, we propose a novel machine that transfers electrical energy between the stator and the rotor via magnetic resonance coupling (MRC). As the energy conversion in an MRC does not require any magnetic core, its mechanism realizes an ultra-lightweight motor for potential use in an energy-efficient electric aircraft. The MRC-based motor, its design, operating principles, starting characteristics, and resonance conditions are discussed in detail herein. Through magnetic analysis, we clarify the essential characteristics of the proposed MRC motor and verify the resonance conditions calculated from the equivalent circuit. Our results confirm that the proposed MRC motor transfers electrical energy between the stator and the rotor, thereby generating torque. We further verify that the resonance conditions derived from the equivalent circuit achieve a resonant state.