SBW 반력 장치용 모터의 코깅 토크, 토크 리플 및 전자기력 고조파 저감을 위한 회전자 현상에 따른 비교 연구

Abstract

In this paper, the development of steering system and SBW (Steer by wire) system are introduced. Also, designs for reducing cogging torque, torque ripple and electromagnetic force harmonics that affect vibration in the motor for reaction force device used in the system of SBW are studied. In addition, according to rotor shape, three types of motors are designed to reduce vibration considering the same design specifications. First, it is designed as a SPMSM (Surface-mounted permanent magnet synchronous motor) type that is advantageous in terms of control. Second, it is designed as an IPMSM (Interior permanent magnet synchronous motor) type advantageous for power density. Third, in order to reduce the use of permanent magnets, it is designed as a CP-PMSM (Consequent pole permanent magnet synchronous motor) type. Using the FEA (Finite Element Analysis), the design parameters that affect cogging torque, torque ripple and electromagnetic force harmonics are identified. Then, the optimal design is carried out by selecting the objective function and constraint conditions. The optimal design result based on the surrogate model depends on how well the surrogate model simulates the performance. Therefore, in the optimal design, an surrogate model is created using the kriging method, and the predicted performance is verified to match the true value. Finally, the performance of these three types of motors is compared to suggest a motor type suitable for SBW.