基于非线性能量俘获机制的直驱浮子式波浪能发电装置研究

A directly driven floater type wave energy converter with nonlinear power-take-off mechanism in irregular waves

以直驱振荡浮子式波浪能发电装置为研究对象,探讨在应用线性和非线性能量俘获机制的情况下,装置在不规则波中的能量俘获情况。基于势流理论,针对垂荡运动,建立浮子与电机的耦合运动方程,应用四阶龙格库塔法数值求解,对非线性能量俘获机制中稳定平衡位置的影响进行研究,对线性和非线性装置在不同谱峰频率的不规则波中能量俘获功率的差异进行分析。结果表明:适当选取稳定平衡位置,非线性装置可以在低频时比线性装置俘获更多能量,且俘获能量频谱带宽更宽,更适应于实际海况中波浪能量俘获。

The energy-capturing performance of a directly driven floater type wave energy converter( WEC) with linear power-take-off( PTO) mechanism and nonlinear one was studied. Based on the linear potential theory,considering heaving oscillation of the WEC,the moti on equations for the floater-PTO coupled system was established and numerically solved using the 4 th order Runge-Kutta method. The influences of the stable equilibrium position of the PTO mechanism on energy-capturing were parametrically studied,the difference among power captures of WECs with linear/nonlinear PTO mechanisms was analyzed. The results showed that a WEC with nonlinear PTO mechanismcan capture more energy in lowfrequency range through selecting a proper stable equilibrium position than a WEC with linear PTO mechanism can,and have a wider bandwidth of the captured energy spectrum; so the former is more applicable for capturing wave energy in actual ocean.