Title : NUMERICAL OPTIMIZATION OF POINT ABSORBER WAVE ENERGY CONVERTER USING LATCH CONTROL

Abstract of Thesis :
Point Absorber wave energy converters (PAWECs) are narrow banded systems with maximum power absorption centered around resonant frequency. As an effort to increase their energy capture bandwidth for a wide range of wave states, a sub-optimal phase control strategy known as Latching is applied. Latching aims to achieve maximum performance by tuning the natural frequency of the device to the excitation frequency. A direct consequence of latching is the onset of viscous drag that modulates the hydrodynamic behaviour of the system resulting in lower power compared to optimal conditions. A nonlinear higher order model is developed for capturing the behaviour of latch-controlled PAWEC under monochromatic wave conditions. A new latching strategy based on the floaters maximum velocity is proposed for nonlinear control design. Results show that latching doubles the energy harvest and helps in achieving stable operation of the device across a range of wave periods.


Keywords : Wave energy converters, Point Absorbers, Numerical modelling, Latching control, Viscous damping.