Performance Comparison of MW Class Tubular Linear Generators for Wave Energy Conversion

Wave energy converters (WECs) have received much attention with the increasing environmental concerns. And the direct-drive WECs are more attractive due to the elimination of intermediate mechanical conversion parts. We have proposed a concept of a WEC device, in which a tubular linear generator (TLG) is directly driven by a heaving buoy. We design a high-temperature superconducting TLG (HTS-TLG), a permanent magnet (PM) TLG, and a copper TLG for the WEC. In this paper, we give a brief description on the conceptual structures and the electrical design method of these three types of TLGs, then show the way of determining main machine parameters considering the basic generator performance (weight, efficiency, and the amount of field conductors/PMs). Design results of these TLGs are finally presented with machine performances and costs compared. We found that the HTS-TLG is the most promising one compared to the other counterparts.