Study on vibro-acoustics of polyphase, fractional slot, surface mounted permanent magnet disc machines

A new analytical technique for axial flux PM machines is introduced in this paper. The basic principles of the new technique are explored, and the differences between radial and axial flux PM machines is discussed. Then calculation program based on MATLAB language is finished. The acoustic noise for 5 kW, 22-poles axial flux surface magnet disc type machine with single-rotor-double-stator is calculated. The calculating results agree well with the measured one. The influence of angle-cut magnetic pole on vibration and acoustic noise is discussed, and the effect of Angle-cut magnetic pole is summed up in this paper. When the harmonic distortion factor has the minimal value, the electromagnetic noise also has the minimal value.