Acoustic Noise Reduction of a High-Efficiency Switched Reluctance Motor for Hybrid Electric Vehicles With Novel Current Waveform

One of the major topics of switched reluctance machines (SRMs) is how to reduce the acoustic noise and vibration without decreasing the efficiency. In this paper, a few novel current profiling methods are proposed to reduce the acoustic noise by flatting the radial force sum and to reduce optimal torque ripple with best efforts to enhance the efficiency. The proposed method is adopted to the 18/12 pole SRM, which has identical outer dimensions and competitive torque, output power, efficiency, and operating region of the permanent-magnet motor used in the hybrid vehicles. It is found that the proposed method can improve not only the radial force ripple characteristic but also the iron loss minimization. The efficiency enhancement is also found to be possible in a few cases depending on the demanding criteria; thanks to the phase shift of the fundamental component of the current waveform. The proposed method is verified in the experiments.