Generator design and characteristics in direct-link wave power generating system considering appearance probability of waves

The energy density of wave power is higher than some renewable energy sources such as wind and solar energy. However, because waves have an irregular reciprocating motion, it is difficult to convert wave power into electricity, and this has restricted the widespread use of wave power. In this paper, a new mechanism to convert wave power into electricity is proposed. It is referred to as a “direct-link” mechanism consisting of a buoy, rack, and pinion. Because of its simple load transfer path, it is expected that the energy conversion efficiency is higher than that of the usual wave power conversion systems. Surface permanent magnet synchronous generators for the proposed system are designed with different numbers of poles. The electrical output characteristics considering the appearance probability of the waves in Shionomisaki are calculated by a dynamic simulation. It is shown that the conversion efficiency of the proposed system is remarkably improved from that of a conventional system.