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 the electromotive force and flux linkage. The analyzed machine would be most appropriate for direct-drive operations.

Key words: Design elements, twin stator, electromotive force and flux linkage