Design optimisation and comparison of tubular permanent magnet machine topologies

The influence of the leading design parameters on the performance of slotless tubular permanent magnet machines, and the relative merits of different tubular machine topologies, are deduced from analytical field solutions. The force capability and force ripple are established as functions of a set of dimensional ratios, with due account of magnetic saturation and subject to a specific thermal constraint. The results provide an effective means of making comparative studies and optimising machine designs, and will aid the design process when addressing a given performance specification.