VP20-06 A Novel Dual Magnetically Geared Halbach Array Based Tubular Linear Permanent Magnet Generator for Wave Energy Conversion

With oceans covering nearly 70% of Earth, harnessing marine energy offers a promising alternative for sustainable power. Among the various types, wave energy is notable for its high power density, but faces challenges in direct-drive wave energy conversion (DD-WEC) due to the low generated voltage and power density, attributed to the slow wave speeds. Enhancing magnetic field density and increasing the translator speed are key to addressing these issues. In an attempt to maximize energy extraction, a dual magnetically geared tubular linear permanent magnet generator with dual armature and dual Halbach array (DMG-TLPMG) is proposed in this paper. This paper presents the novel integration of two tubular linear permanent magnet generators (TLPMG) and two tubular linear magnetic gear (TLMG) machines into a single machine. The proposed design features dual armatures, identified as the inner and outer armatures, which are positioned to convert the kinetic energy of waves into electrical power. This design is shown in Fig.1. The translator is hollow and cylindrical which has embedded ring magnets on both the inner and outer circumferences. It induces voltage in both the armatures with a single stroke. This design has an additional advantage of fault tolerance, as each armature is electrically isolated. Further, the magnetic gearing effect enhances the rate of change of the magnetic field, thereby increasing the generated voltage as the translator's stroke is constrained to the motion of the wave. The permanent magnets (PMs) are systematically arranged as a Halbach array as shown in Fig. 1. It achieves two primary objectives, segregates the magnetic fields of the inner and outer PMs resulting in distinct magnetic fields for the outer and inner armatures, and it enhances the magnetic field density in both the armatures. For the design, wave data from the cities Varsova and Karwar in India are considered. The analytical analysis is carried out for the proposed generator and the findings are correlated with the 3-D finite element analysis.