TY - JOUR
TI - Power take-off damping control performance on the power conversion of oscillating-buoy wave energy converter
AU - Sun Weijie
AU - Zhou Yujie
AU - Wan Zhengang
AU - Zhou Xiaoguo
AU - Zhang Wanchao
JN - Thermal Science
PY - 2021
VL - 25
IS - 6
SP - 4107
EP - 4115
PT - Article
AB - The power take-off (PTO) damping mechanism is very important to the motion  and power conversion for the wave energy converters. Based upon the  potential flow theory, the series expression with unknown Fourier  coefficients of velocity potential function of the basin where the  cylindrical floating buoy is located is obtained by using the eigenfunction  expansion method. According to the characteristics of the PTO damper, the  motion and wave energy conversion characteristics of the float under the  linear and non-linear PTO damping are studied, respectively, and the  over-damping problem under the linear PTO damping is emphatically explored.  The results show that the influence of PTO system with low velocity index on  the motion of the device is mainly reflected in the PTO damping coefficient.  With the increase of damping coefficient, the resonance frequency of the  wave energy device decreases gradually, but the decrease amplitude is very  small. The non-linear characteristics of PTO system cannot change the  optimal capture width ratio of the float, but the large velocity index can  effectively improve the damping capacity of PTO system. At lower and higher  frequencies, the optimal PTO damping obtained by the analytic algorithm will  make the device in an over-damped state. The highest frequency in the low  frequency part and the lowest frequency in the high frequency part which  need to be modified will gradually decrease with the increase of radius and  draught.