{'fraction_non_alphanumeric': 0.01557632398753894, 'fraction_numerical': 0.0, 'mean_word_length': 4.756272401433692, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Power take-off damping control performance on the power conversion of oscillating-buoy wave energy converter

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.