Comparison of the acoustic noise of a flux switching and a switched reluctance drive

This paper describes the results of a comparison between the acoustic noise produced by a two-phase switched reluctance drive and a flux switching motor and drive. For the comparison, two external rotor machines were constructed from identical mechanical parts, and the same lamination stacks. Test results show that there is over 2 dB less acoustic noise from the flux switching topology relative to the equivalent two-phase switched reluctance machine. Finite element analysis is used to calculate the radial force profiles of the two motors during normal rotation and it is shown that further analysis of this data provides supporting evidence to the measured data and confirms the experimental results. The improved acoustic noise and vibration characteristics, coupled with the dramatic simplification of the power converter offered by the flux switching drive makes it a very attractive, low cost, low acoustic noise, variable speed drive.