Wave Energy Absorption in Irregular Waves by Feedforward Control System
Wave Energy Absorption in Irregular Waves by Feedforward Control System
复制标题
前馈控制系统对不规则波的波能吸收
DOI：
10.1007/978-3-642-82666-5_23
复制
发表时间：
1986
影响因子：
0.8
通讯作者：
Shoichi Nakamura
中科院分区：
文献类型：
--
作者：
S. Naito;Shoichi Nakamura
在过去的几年里，已经提出了许多关于海洋波浪能量吸收的理论和实验论文[1]。其中许多是关于规则波中的波能吸收特性和最佳控制条件的。实际上，这是不够的，更多的兴趣必须集中在不规则波的问题。由浮体和外部机构组成的发电系统在不规则波中吸收的波浪能有两个分量，一个是稳定分量，另一个是脉动分量。本文对这两个分量的有关问题进行了研究。一个是最优控制理论，以获得最大的平均能量的不规则波有关的稳定部分，另一个是制定的频谱吸收波能量有关的波动部分。在规则波中完全吸收波能的最佳条件是众所周知的。然而，为了建立不规则波中的波能吸收系统，有必要在时域分析的基础上考虑该问题，因为最佳条件取决于波的频率，并且不规则波包含许多具有不同频率的分量波。提出了一种利用外部机构在浮体前方一定距离处测量入射不规则波浪，并利用测量的波浪数据进行瞬时控制以提高效率的系统，称为“波浪能量吸收前馈控制系统”。此外，从实用的角度讨论了波传播特性中的因果律，因为该系统中使用的波传播核函数通常不满足因果律。
A number of theoretical and experimental papers on ocean wave energy absorption have been presented over the past few years [1]. Many of them are concerned with the characteristics of absorbed wave energy and the condition of optimum control in regular waves. Practically this is not sufficient, and more interest must be focused on the problem in irregular waves. Absorbed wave energy in irregular waves obtained by a generating system which is composed of a floating body and external mechanism has two components, one is a steady component and the other is a fluctuating one. In this paper, some problems about the two components mentioned above are studied. One is the theory of optimum control to obtain the maximum mean energy of irregular waves related to the steady part, and the other is the formulation of the spectrum about absorbed wave energy related to the fluctuating part. The optimum conditions for complete absorption of wave energy in regular waves are well known. However, to establish the system of wave energy absorption in irregular waves, it is necessary to consider the problem on the basis of the time domain analysis, because the optimum conditions depend on wave frequency and irregular waves contain many component waves having different frequencies. A system, in which the incident irregular waves are measured at a certain distance in front of the floating body with the external mechanism, is controlled instantaneously to improve the efficiency by using the measured wave data, called “Feedforward Control System for Wave Energy Absorption” is proposed. Furthermore, the law of causation in the characteristics of wave propagation is discussed from the view point of practical approach, because the kernel function of wave propagation, which is used in this system, does not usually satisfy the law of causation.