This paper presents a novel two-layer subharmonic vernier machine (2L-SHVM) explicitly designed for electric propulsion applications. The proposed topology features a unique stator configuration with two independent three-phase winding sets powered by separate current source inverters, enabling precise control of sub-harmonic magnetic field components. Through comprehensive finite element analysis (FEA), we demonstrate that the 2L-SHVM achieves a 6.2% increase in average torque, 19.58 Nm and 18.44 Nm, respectively, and a substantial 63.5% reduction in torque ripple, 8.49% and 23.25%, respectively, compared to conventional subharmonic vernier machines. The design incorporates optimized winding distributions and rotor skewing techniques, with a 4 degree continuous skew providing the optimal balance between torque production and ripple reduction. Furthermore, the proposed machine exhibits improved efficiency at 72.62%, marking a 13.69 percentage increase over traditional designs. These results establish the 2L-SHVM as a promising solution for applications requiring high torque density and precise control, particularly in transportation electrification.
