Comparison of Position-Independent Contactless Energy Transfer Systems

This paper presents a comparison of position-independent contactless energy transfer systems by means of an inductive coupling, as a solution to overcome moving cables in emerging mechatronic applications with a linear moving load. A 2-D electromagnetic model of the contactless energy transfer system is derived and applied to six different topologies, which have either air-cored coils or a combination of salient or nonsalient magnetic cores. A parametric sweep is performed to obtain an optimal parameter set for each topology, suited for a power transfer of 1 kW with a position-independent mutual inductance between the primary and secondary coils. Comparison among the topologies shows that slotted topologies are less suited for a constant power transfer and that the geometry can be optimized for a mutual inductance variation below 3% along the linear movement.