Torque capability comparison of two magnetically geared PM machine topologies

This paper presents a comparison of the torque capability of two PM machines with integrated magnetic gears for low speed, high torque applications. The machines are also compared against a more conventional fractional-slot PM machine to evaluate the benefits of the geared machines. The comparison is based on the optimal torque per active mass that could be achieved within a given volume. The machines are optimized using 2D finite element (FE) analysis and the optimal designs are further evaluated using 3D FE analysis. For the geared machines, an optimization procedure is employed which ensures that the gear and stator parts are well matched.