Comparative electromagnetic parameters for alternative motor types

A number of areas relevant to battery powered electric propulsion are of interest to the author, and colleagues. In particular, one project at an early stage concerns the development of electric propulsors for unmanned underwater vehicles, in forms powered both by umbilical connection to a surface station and by on-board batteries. This is a detailed global systems design study, involving separate but interacting strands and including: selection of motor type; possibility for the development of purpose-designed motors of novel configuration, and their electromagnetic design; choice of switch devices and inverter design; choice of battery system; transfer characteristics between electrical power input to the propulsor and force-on-water output; control strategies; system simulation; cost/mass/reliability/efficiency trade-offs with respect to all the foregoing features. Here, some fundamental electromagnetic design parameters are tabulated for five selected machines, of widely differing type. These reveal the diversity that may be observed in practice and provide an instructive insight into the influence of various parameters on performance