Experimental Improvement of Speed–Torque Characteristics in Magnetic-Geared Switched Reluctance Motor

In-wheel direct drive motor systems for electric vehicles (EVs) have garnered significant attention because they integrate traction motors directly within the driving wheels, eliminating the need for transmission elements and resulting in a compact design and ease of maintenance. Among novel in-wheel motor designs, a magnetic-geared switched reluctance motor (MG-SRM), which combines a switched reluctance (SR) motor and a flux-modulated-type magnetic gear (MG), is notable for achieving the wide speed–torque characteristics required for EVs. However, the torque of the MG-SRM in high-speed regions has been relatively small. Therefore, this article focuses on improving the torque by advancing the excitation start angle of the SR motor. Experimental results demonstrate that speed–torque characteristics improve, especially in medium-speed regions. When applying the proposed method, the current density-torque characteristics decrease. Nevertheless, when focusing on the same torque, the efficiency remains unaffected because the output power increases. Moreover, when focusing on the same rotational speed, the efficiency improves as the torque increases.