Design procedure and implementation of a high-efficiency PMSM with reduced magnet-mass and torque-ripple for electric vehicles

Abstract

In the near future, the reduction in petroleum and emission restrictions, especially with the development of batteries, electric motors and power electronics, will inevitably lead to the further influence of electric vehicles. In this study, it is aimed to design and implement internal permanent magnet synchronous (IPM) motor with high efficiency and power density. A flowchart covering the design process was developed focusing on the design of the IPM motor. The main dimensions of the machine to be designed are determined from the vehicle requirements. With the detailed analytical analyzes, the process of determining the basic dimensions of the motor and winding structure was applied and numerical analyses were carried out by the finite element method. The effect of space harmonics, radial forces and cogging torque are reduced due to the unbalanced winding created by using the single slot number (57-slot/8-pole). Throughout the design process, optimizations on the structure, size, and position of the magnets have resulted in minimizing the magnet amount to provide the required performance and torque-speed characteristic. Thermal and structural strength analyzes of the motor were made and prototype production and tests on the vehicle were successfully performed..