Acoustic Modeling and Prediction of Ultra-High Speed Switched Reluctance Machines Based on Finite Element Analysis

摘要

High-speed switched reluctance machines (SRMs) have been a timely topic recently due to its intrinsically simple and robust geometry. However, for ultra-high speed SRMs over 100,000 rpm, the acoustic noise is a very significant issue in many applications. Estimating the acoustic output of ultra-high speed SRMs accurately is obviously very important in any effort to reduce the noise level. In this paper, a multi-physics acoustic modeling and prediction of ultra-high speed SRMs is presented based on finite element analysis (FEA). First, a 3D electromagnetic FEA is conducted to calculate the radial force on the stator teeth, which is the origin of the noise. Then, a modal analysis and a harmonic response analysis are shown in the frequency domain to estimate he natural frequencies and the vibration of the whole motor with the case and support included, using the calculated radial force as the input excitation. After that, an acoustic response analysis is done to estimate the sound pressure level (SPL) using the superposition of the surface vibration information from the harmonic response analysis. Finally, to verify the proposed model, experiments are done to measure and compare the SPL of a 4/2 ultra-high speed SRM at 100,000 rpm. The results show that the Aweighted SPL of the motor is as high as 115 dB at 10 mm away from the motor, which matches the simulation result (113 dB) quite well.