Marine current turbines and generator preference. A technology review

Abstract

Marine current power is a significant energy resource yet to be exploited for electricity production. Several novel turbine technologies can be found on the market, and new ones emerge every year. This study found that the most popular choice seems to be the axial flow three-bladed turbine, although the industry has not yet converged to one preferred technology. An overview of the turbine technologies is presented with drive train layout for each device, if this information is obtainable. The majority of manufacturers use geared (mechanical or hydraulic) solutions, and an induction or a synchronous generator. The few direct drive systems all use PM synchronous generators. For prototype turbines there is a trade-off between choosing a proven generator technology that is not optimised for the application, and using a prototype machine that may reduce the number of design iterations.