On the Resonance Characteristics of the Float Type Wave Power Generation Device

Abstract

This paper examines the resonance characteristics of the wave power generation device which consists of pulley(s), wire(s), float(s), counterweight(s) and ratchet mechanism. The resonance analysis model introduces the relative displacement between the water level and the float's position into the dynamics model for the system in operation. The equations of natural frequency, ratio of wave frequency to natural frequency of the system, damping ratio and magnification ratio have been given. Further, the characteristics of average electric power output and maximum wire tension have been examined for wave periods near the natural period of the system. The relationship between natural period of the system and float dimensions, especially float's diameter to height ratio, has been examined. As an example, the annual average electric power output and energy conversion efficiency have been evaluated for the system with natural period near the dominant wave period when it operates off Kobe port where the annual variation of the wave period is small.