The rare earth permanent magnet (PM) is widely used for traction motors of hybrid and electric vehicles. These motors have more torque density compared to any other type of motors. However, these PMs have the problems of limited reserves, unstable supply, and high cost. For solving these problems, concentrated flux synchronous motor (CFSM) and multi‐layer interior permanent magnet synchronous motor (IPMSM), using ferrite PMs, are compared in this study. The CFSM and multi‐layer IPMSM are introduced and compared with regard to shape, size, electric parameter, and motor characteristics. In addition, two types of motors are fabricated and tested in order to verify their performance and feasibility. Finally, comparing the merits and demerits, the comparative motor types are estimated in this study.

No abstract

No abstract

No abstract

This study deals with a robust design for cogging torque reduction considering the production tolerances of motor sub-components, which is related to the dimensions of the permanent magnet and stator core shape. A 14-pole and 12-slot fractional slot concentrated winding motor is employed as the design model. Prior to a robust design, an initial model was implemented to satisfy the torque demand within some constraints. In the robust design, the main design variables were first selected for the design of experiment (DOE). The interaction effects were investigated using the full factorial design, which is one of the DOE techniques. Next, the direction of design variables to minimise the cogging torque and improve the signal-tonoise ratio were confirmed using the Taguchi method. Then, the response surface methodology was implemented based on the result from the Taguchi method to yield an optimum value of the design variables and approximate equivalent polynomial equation. Finally, the normal distribution curve of the cogging torque was simply determined by the equivalent polynomial equation using the Monte-Carlo method taking production tolerances based on the process capability of the sub-components into consideration.