| Abstract: | A wave energy converter and method for extracting energy from water waves
maximizes the energy extraction per cycle by estimating an excitation
force of heave wave motion on the buoy, computing a control force from
the estimated excitation force using a dynamic model, and applying the
computed control force to the buoy to extract energy from the heave wave
motion. Analysis and numerical simulations demonstrate that the optimal
control of a heave wave energy converter is, in general, in the form of a
bang-singular-bang control; in which the optimal control at a given time
can be either in the singular arc mode or in the bang-bang mode. The
excitation force and its derivatives at the current time can be obtained
through an estimator, for example, using measurements of pressures on the
surface of the buoy in addition to measurements of the buoy position. A
main advantage of this approximation method is the ease of obtaining
accurate measurements for pressure on the buoy surface and for buoy
position, compared to wave elevation measurements. |