Influence of Design Elements on the Induced-EMF and Flux Linkage of Double Stator Permanent Magnet Machine

Abstract

The influence of design elements such as conductor space opening / stator-tooth pitch proportion (β), permanent magnet width (PMw), rotor  circular width (Rth), aspect ratio (Sr), stator tooth-width (Tw), outer rotor pole arc / pitch proportion (ϒ1) and inner rotor pole arc / pitch proportion  (ϒ2), on open circuit machine performances such as flux linkage and induced electromotive force (EMF) is investigated in this study using finite  element method. The studies show that for each machine element, there is a point or dimensional position upon which the largest machine output  performance is realized. Moreover, smooth control of any given electrical machine would also depend on these structural elements. The largest  induced electromotive force is obtained when the conductor space / rotor pitch proportion, permanent magnet width, rotor circular width, aspect  ratio, stator tooth-width, and outer and inner rotor pole arcs / pitch proportion is: 0.7, 5mm, 5mm, 0.7, 6mm, 0.7 and 0.3, respectively.  Corresponding largest flux linkage amplitudes also occur at these geometric values, owing to the direct relationship between electromotive force  and flux linkage. The analyzed machine would be most appropriate for direct-drive operations.