Design aspects for in-vehicle IPM motors for sustainable mobility

Abstract

In battery electric vehicles, permanent magnet synchronous IPM motors are gaining more and more ground due to their high power density and high-efficiency operation. Many research examine their specific characteristics. In order to reach a desired total torque, low torque ripple, high efficiency, many pre-plannings have to be executed. The modern age engineering industry can rely much on complex simulation software, such as MotorAnalysis – PM. In this paper, an initial IPM motor design with delta magnet arrangement was created for vehicle application. This study had a strong focus on finding correlation between rotor layout arrangement and crucial motor operationial attributes, such as: torque components, torque ripple, cogging torque and efficiency. Time stepping magnetostatics FE and time stepping transient FE simulations were used. Each arrangement changement held its own simulation file, thus the effect of each change could have been separately examined. Arrangements, where the distance between magnets is smaller, resulted in greater torque and efficiency. Usage of enlarged magnets had the same results. Size should be increased and distance should be decreased with care to avoid a growth in torque ripple.