Vibration and Acoustic Noise Reduction in Switched Reluctance Motor by Selective Radial Force Harmonics Reduction

This article presents a novel method for vibration and acoustic noise reduction in a three-phase 6/10 switched reluctance motor (SRM). The test machine has major vibration and acoustic noise at the 2${\text{nd}}$, 4${\text{th}}$, 5${\text{th}}$, 7${\text{th}}$, and 8${\text{th}}$ harmonics. Accordingly, a novel method called “selective radial force harmonics reduction” is proposed. The proposed method selectively reduces the specific radial force harmonics at the stator teeth. By reducing the specific radial force harmonics such as 2${\text{nd}}$, 4${\text{th}}$, 5${\text{th}}$, 7${\text{th}}$, and 8${\text{th}}$, the corresponding vibration and acoustic noise can be reduced significantly in the test machine. In this study, a current calculation for the proposed method is introduced. In addition, finite element analysis and experiments are conducted to verify the effectiveness of the proposed method. Compared with a conventional square current, the experimental results show that the overall sound pressure level is reduced by 7.1 dBA using the proposed method at the rated speed and torque. The dynamic conditions of the test machine using the proposed method are also presented. As a result, the proposed method is effective in reducing vibration and acoustic noise in the three-phase 6/10 SRM.