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This paper presents innovative methods to resolve the two challenges that occur when using a switched reluctance motor (SRM) as a traction motor for a compact electric vehicle (EV). Electric vehicles (EVs) are seeing a rise in popularity today and the demand for further advancement of EV technologies will continue to grow. Induction motors and interior permanent magnet motors (IPMs) are most commonly used traction motors for EVs. In this project, we focused on the development of a switched reluctance motor (SRM) as an alternative motor for compact EVs, leveraging the following benefits of SRMs: 1) SRMs, which require no permanent magnets, have no drag torque, enabling clutchless motor applications, and 2) SRMs demonstrate high efficiency in the high-speed rotation range. In applications of SRMs as EV drivers, however, there are two challenges to be resolved. The first challenge is that SRMs have significant torque ripples due to the principle of torque generation.

As an appropriate material for automotive thermoelectric generators, which directly convert waste heat of exhaust gas into electricity, we have developed Mg2(Si1-xSnx) thermoelectric materials with high thermoelectric performance. The performance is evaluated with the dimensionless figure of merit (ZT), and the ZT has been improved through the development of the fabrication process and the investigation of the optimum composition and dopant element. A novel liquid-solid reaction synthesis method incorporating hotpressing for the sample fabrication was effective in reducing the thermal conductivity. The n-type Mg2(Si0.50Sn0.50) doped with Sb attained a high ZT of 1.1 at 620 K. The p-type Mg2(Si0.25Sn0.75) doped with Li and Ag simultaneously achieved a ZT of 0.3 at 600 K. The effective maximum power of n-type thermoelectric element and that of p-type were calculated with the thermoelectromotive force and the mean resistivity.