Nonlinear stiffness system application in wave energy conversion

Nonlinear stiffness system (NSS) was applied to a point absorber (PA) for studying the influence of the nonlinear behavior on wave energy converter (WEC). Static characteristic of NSS was analyzed. Moreover, time domain numerical simulations based on Cummins’ equation was utilized to evaluate the effects of power take-off (PTO) damping, system stiffness and geometry dimensions. The results in regular waves presented that nonlinear stiffness system could improve the efficiency of wave energy conversion by both pushing up the natural period and broadening resonance bandwidth of system. The more practical simulation in irregular waves indicated that the application of nonlinear stiffness system was a promising approach in improving the efficiency of wave energy conversion.