Design and Experimental Analysis of a Novel Coreless Two-Phase Resonant Motor

This article proposes a novel coreless two-phase resonant motor (CTRM) with a high torque per unit volume density (77.6 N・m/m3) based on the properties of mag-netic resonance coupling. The motor comprises a two-phase orthogonal winding in both the stator and rotor arranged radi-ally on 3-D printed, nonmagnetic cores made from reinforced plastic fiber. In the proposed design, the conventional mag-netic circuit in electric motors is replaced with a resonant cir-cuit. To achieve this, resonant capacitors are connected across the separate two-phase windings to produce the required resonance behavior in the machine. Analytical mod-els of the machine’s key characteristics, including induc-tance, generated torque, and capacitance estimation are derived and verified with an equivalent simulation model through finite element methods. The objective is to efficiently integrate electric machine design concepts with inductive magnetic resonance coupling technology to enhance the out-put torque in an air-cored machine. Finally, a hardware proto-type is developed, and the effectiveness of the CTRM is validated through experimental measurements and analysis. To evaluate the significance and merits of the proposed motor, a case-control experiment without resonant capacitors is set up. The results demonstrate that the proposed CTRM achieves improved performance with larger air-gap compared to related air-cored resonant induction machines.