隨著傳統能源匱乏及其造成之汙染嚴重，世界各國對於開發再生能源的態度日益積極，其中波浪能具有高能量密度等特性及台灣地理和氣候因素等條件使波浪能在我國相當具有發展價值。而本實驗室近年來也致力於波浪獵能器，目前已有數學、數值模型與實際建立實驗原型等相關研究，其中實驗原型為以振盪浮體形式為基礎建立的波浪獵能器，最終實驗結果表明此裝置具有許多可改善空間。本研究主要目的為在實際變更原型設計與部署前，透過建立獵能器浮體運動方程式以機電系統之阻尼與波浪系統之附加質量與輻射阻尼的角度探討與優化獵能器。
首先對獵能器建立了機電測試平台，以最大傳輸功率定理對發電機與外部負載電路進行阻抗匹配得知在負載電路在300 Ω 時發電機具有最大能量輸出，同時優化儲能電路使其獲得的能量達到原本的1.13倍，再透過遲滯阻尼將獲得能量轉換成阻尼後得知阻尼與浮體運動頻率關係式且其與浮體運動振幅無關。而儲能電路隨著電容值上升獲得最佳能量輸入的所需運動週期數上升及浮體運動頻率增加時最佳儲能電容值下降。數值計算部分則透過數值水槽與獵能器浮體的線性模型將入射波浪與浮體的交互作用分解成散射效應與輻射效應兩者疊加並對其分別建立模型，並透過線性波理論與造波器理論驗證其可信度和散射模型與文獻探討在水槽中反射與再反射波影響。最後透過獵能器浮體運動系統的方程式後將實驗與數值計算結果整合獲得浮體運動行為。再來透過浮體運動計算附加質量與輻射阻尼，得知隨著Froude數上升而附加質量與輻射阻尼會下降，且附加質量與獵能器機構質量數量級相同。透過阻尼比發現發電機規模與波浪獵能器規模不匹配，再來使用能量比率分析能量耗散與轉換的平衡。最後透過上述論點，可知此現有獵能器原型未來可調整發電機規模、浮體幾何、機構質量與匹配入射波共振頻率來產生共振等方向來優化獵能器。

The world demands increasingly more use of renewable energy as the traditional energy sources cause environmental pollution and are becoming more depleted. To fulfill such demand, wave energy is a good alternative for Taiwan because of its high energy density and the favorable geographic and climate conditions herein. Thus our research group has devoted to the development and optimization of a wave energy converter (WEC) of the oscillating body (OB) type. But to optimize our WEC prototype, and to expedite the design process of real-world WEC system as well, it proves useful to understand the electromechanical characteristics of the electric components of a WEC and the hydrodynamic forces exerted on the buoy of the WEC by incoming water waves. Hence in this work we present a methodology for understanding the aforementioned important factors in WEC system design. Specifically, the effective mechanical damping of the electric component of a WEC is determined by exciting the WEC with periodic forcing of various amplitudes and frequencies. Meanwhile, the hydrodynamic forces acting upon the buoy of a certain WEC design by incoming water waves of various frequencies are computed numerically, and then are used to determine the added mass and radiation damping effects on the buoy motion. With the two sets of results at hand, the WEC system dynamics then can be analyzed and optimized.
In particular, our experimental results on the electromechanical characteristics of the WEC system indicate that the power output can be maximized by impedance matching of the electric components. Meanwhile, the effective damping of the electric components appears to be rather insensitive to the buoy motion amplitude. In the numerical calculation of the hydrodynamic forces, first we construct a linear mathematical model of the numerical water tank (NWT) with the presence of a WEC buoy, and decompose the interaction between the incident waves and the buoy into the superposition of scattering and radiation effects. Next, the motion of the buoy is calculated by solving the equation of motion in which the experimental and numerical results are integrated. And the results indicate that the WEC system dynamic can be optimized by adjusting the size of the generator, the geometry of the buoy, the mass of the mechanism, and by matching the natural frequencies (or impedances) of the various components in a WEC.

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