Design of a stand-alone wave energy plant

One of the main reasons for the wave energy generation not yet gaining popularity as a renewable energy source is the lack of work relevant to the design of a stand-alone wave energy power plant. The major issue in the design of such a plant feeding variable AC load and maintaining a regulated voltage and frequency at the output, concerns the control of the plant itself. In this work, an impulse turbine is used to convert differential air pressure due to oscillating water column into mechanical shaft power. A permanent magnet based alternator driven by this turbine generates variable voltage variable frequency AC, which is rectified to DC by a diode bridge. At the second stage, a DC motor - alternator set converts this into fixed frequency, fixed voltage AC acceptable as a utility AC supply. Results obtained from a steady-state model simulated using MATLAB -Simulink are presented. Actual data recorded by the Indian wave energy plant have been used to validate the results. Copyright © 2005 by The International Society of Offshore and Polar Engineers.