The influence of the leading design parameters on the performance of slotle
ss tubular permanent magnet machines, and the relative merits of different
tubular machine topologies. are deduced from analytical field solutions. Th
e force capability and force ripple are established as functions of a set o
f 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 th
e design process when addressing a given performance specification.