Double and single sided tubular linear Permanent Magnets generator for the Wave Energy conversion

The main purpose of this paper is to carry out a preliminary comparison between two linear tubular synchronous, three-phase generators for WEC (Wave Energy Converter) applications. The first device is a conventional one, with a single slotted stator and a mover which is composed of Permanent Magnets (PMs) arranged in an Halbach array. The second configuration has two concentric stators and a mover with a system of North-South alternating magnetic poles. This mover slides in the airgaps between the two stators. The comparison was performed maintaining the same size (outer radius of the devices and length of the stators) and an equal volume of permanent magnets placed onto the slider part. All the simulations were carried out using a FEM code, capable to take into account the nonlinear behavior of the magnetic materials and the irregular movement imposed by the sea wave profile.