Feasibility Study of a Nonlinear Wave Energy Converter With Variable Buoy Geometry

This paper presents a nonlinear control design technique that capitalizes on an hour glass (HG) variable geometry wave energy converter (WEC). The HG buoy is assumed to operate in the heave motion of the wave. The unique interaction between the HG buoy and the wave creates a nonlinear cubic storage effect that produces actual energy storage or reactive power during operation. A multi-frequency Bretschneider spectrum wave excitation input is reviewed for the varying steepness angle profile for refinements to the respective sea state. As part of our feasibility study, the numerical simulations showed further increase in power generation over the constant steepness angle baseline. As a result this will increase efficiency of operation and power generation by reducing conventional buoy size and weight, respectively.