Study on Maximum Wave Power Efficiency of New Type Point Absorption Converter under External Electrical Resistance

• Main Authors: Chen, Hung-Yi, 陳弘彝
• Other Authors: Weng, Wen-Kai
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/6pjjxv

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 105 === This study investigates the best resistance of a power generator within a point absorber wave energy converter, which generates the maximum power, through hydraulic experiments. From the maximum power transfer theorem, the maximum power is achieved when the internal resistance of the power generator equals to the external resistance. The point absorber wave energy converter is composed of three systems, which extract, transmit and convert wave energy into electricity. The experiments were conducted using a physical model of the scale ratio 1:10 under combinations of system parameters, including load resistance (Ω) of the power generator, speed ratio (SR) of a gearbox, etc., and wave conditions of different wave periods (T) and heights (H). Different measured results of the rate of amplitude operation (RAO) of the buoy heave movement, the torque applied to the power generator, rotational speed of the power generator as well as the voltage, current, and power of the load resistance were analyzed to investigate the extraction-transmission efficiency and power efficiency of the point absorber wave energy converter. The results show that the internal resistance of the power generator does not change for different wave heights. However, it decreases with the increase of the wave period and the decline of the speed ratio. The extraction-transmission efficiency and power efficiency of the point absorber wave energy convertor do not differ much for different wave heights. Instead, they increase with the decline of the wave period and the increase of the speed ratio. Under the conditions of the study, the results show the maximum extraction-transmission efficiency can reach 73% and the power efficiency can reach 67% for a wave period of 1.6 s, a wave height of 20 cm, and the speed ratio of 9.46. Keywords: Point Absorber Wave Energy Converter, Maximum Power Transfer Theorem, Maximum Power Generation Efficiency, Extraction-Transmission Efficiency