Traction Drive Motor for Small EVs Using Mass Producible Amorphous Laminated Cores

ABSTRACT This study presents the development of a small electric vehicle (EV) traction drive motor using Fe‐based amorphous laminated cores that can be mass produced. The following innovative technologies are developed to realize the amorphous laminated core: (1) production technology for thicker amorphous alloy foils to reduce the number of machining operations and (2) punching press technology for amorphous alloy foils that improves the usability of the tool life and maintains quality. The interior permanent magnet synchronous motor (IPMSM) using the amorphous laminated core is designed to be compatible with a 4.5‐kW‐class small EV traction drive with high efficiency while satisfying the required torque characteristics. A prototype of the designed IPMSM was manufactured and evaluated. The test machine achieves a maximum efficiency of 98.7% and a wide range of efficiencies exceeding 97%. Additionally, the prototype motor exhibit improved efficiency in all operating points compared with a prototype manufactured using an electrical steel sheet.