A Spiral Translator Permanent Magnet Transverse Flux Linear Generator Used in Direct-Drive Wave Energy Converter

Direct-drive wave energy converter (DD-WEC) simplifies the structure and improves the efficiency of wave energy conversion. Permanent magnet transverse flux linear generator (PMTFLG) combines the merits of transverse flux linear generator (TFLG) and permanent magnet linear generator (PMLG), and is suitable for low-speed high thrust density applications, like DD-WEC. However, it suffers from a significant demerit which is the high cost due to the rare earth permanent magnets (PMs). A stator-PM spiral translator PMTFLG (ST-PMTFLG) is proposed in this article. Armature winding and PMs are arranged in outer stator and inner stator, respectively while the translator is made of spiral steel blocks and nonmagnetic blocks. Similar to the magnetically geared machine, the proposed topology is suitable to be used in low-speed long-stroke application. Results show that ST-PMTFLG has advantages of low PM consumption and high thrust density. The thrust per PM volume of 12/11 ST-PMTFLG is 4.18 MN/m 3 .