一种基于DEG的全柔性波浪能发电机工作机理及关键技术研究

基于电磁发电原理及现有相关技术的波浪能发电成本高昂，难以实现商业化。本项目基于对介电弹性体发电机（DEG）的研究基础，提出一种具有无穷自由度的全柔性波浪能发电机（DE-WEC）设计的新思想。其特点是作为波浪能收集装置的弹性体管具有无穷自由度，可实现与波浪“全频耦合”，波浪能捕获能力强；作为电能转换系统的DEG与弹性体管融合为一体，结构简单、电能转换效率高，成本低。主要研究内容：①基于弹性体线性理论和数值计算方法，研究弹性体管内、外部流体及其纵向运动、管壁结构特性的控制方程及耦合关系，建立发电机的数学模型、模态幅值方程，及耗散功率方程、净功率和总功率方程。②开展一种DE-WEC电荷管理新方法的研究。该方法将自传感电容与发电循环融为一体，提出一种直接算法，无需外部传感器、无需已知波浪参数，以获得最高发电效率为目标，实现发电循环的最优控制。③样机设计与实验，验证理论模型与电荷管理最优算法。

The issues of degree freedom of Wave Energy Converters(WEC) are inherent linked to rigid WECs with a small number of Dof. Most of conventional WECs are based on rigid hulls capturing the forces from waves and transmitting the work to conventional hydraulic or electromechanical the Power Take Off(PTO) through a limited number of rotational or translational joints. Because of this,it can be found that conventional WECs typically use an excessively large ratio of structural weight/power produced and also require heavy offshore maintenance. As a consequence the cost of energy produced with conventional WECs will not be able to go below a certain level due to incompressible structural and operational costs. It make it difficult for the wave energy industry as a whole to produce sufficient volume to benefit from the learning curve and economy of scale.. Based on the proposed issues,we have proposed a DE-WEC model with a flexible tube that also serves as PTO.It is made of a long elastomeric tube closed at both ends and filled with slight pressurized sea water.This DE-WEC has an infinite number of resonance modes.It is therefore capable to passive operate at resonance for all wave periods of interest,so it can efficiently harvest wave energy without complex active controls.The PTO of this DE-WEC is made of Dielectric Elastomer Generator(DEG).As this DE-WEC tube is deformble,DEG has been an obvious choice to make for its PTO. DEG are fabricated with elastomers,hence they can already form part of the tube of the DE-WEC.Merging the DE-WEC tube structure and the PTO function is one of the greatest achievement of the DE-WEC. In this project,a linear mathematical and numerical model for analysing the dynamic response of the DE-WEC will be described. A set of governing equations should be formulated for flow outside ,inside the tube and the behaviour of the tube wall. Using spectral decomposition, the equation of motion for the response of tube in waves,and the equation for the time evolution of the modal amplitude ,the mean power disspated in the material,the net extracted power will be derived. Furthermore,we present a new method for charge management that integrates self-sensing capabilities into a DE-WEC cycle. The method applies a straightforward algorithm to determine the moment of desired charge/discharge for a chosen cycle. Experiments will be carried out on a scale model of DE-WEC in the wave tank. Numberical results will be compared with experimental results.Estimates will be made for the energy performance of a prototype.