千瓦级小型液压式波浪能装置能量转换系统研究

针对小型海洋观测仪器用电需求,研究高效、可靠的小型液压式波浪能装置能量转换系统。在实验室建立一套3 kW的液压式波浪能能量转换系统,进行不同电阻负载、不同蓄能体积以及不同控制策略的液压系统试验,获得PTO效率曲线及各发电过程的特性曲线,详细分析不同控制策略的能量转换特性,得到PTO效率随阻值的增大趋于平稳、蓄能体积基本不影响PTO转换效率的结论,验证有蓄能器无控制器型直冲式能量转换系统的可行性。     

鹰式波浪能发电装置发电系统研究

文章首先对鹰式波浪能发电装置能量转换系统进行分类,分析了各系统的组成及工作原理,设计了一种液压式和直驱式组合的发电系统,通过模型试验优化了系统中的参数配置,提高了能量转换效率,最后通过实海况试验验证了"鹰式一号"波浪能发电装置的发电系统设计方案的可行性。     

波浪能风能的联合发电装置

简要介绍了波浪的生成及特性。对波浪能和风能的综合利用进行了研究,并研制成发电系统。     

波浪能发电技术研究进展

波浪能是一种清洁可再生的新型能源,已经吸引了各国研究者的目光,开展了相关的研究并已取得一定的成果。文章介绍了各种波浪能发电装置的原理,对海洋波浪能发电装置进行了分类,总结了几种典型海洋波浪能发电装置的优缺点,列举了一些国内外较为成功的波浪能示范电站,并针对现阶段国内外研究现状指出今后波浪能发电装置的发展趋势及前景。     

波浪能发电技术研究进展

摘要： 波浪能是一种清洁可再生的新型能源,已经吸引了各国研究者的目光,开展了相关的研究并已取得一定的成果。文章介绍了各种波浪能发电装置的原理,对海洋波浪能发电装置进行了分类,总结了几种典型海洋波浪能发电装置的优缺点,列举了一些国内外较为成功的波浪能示范电站,并针对现阶段国内外研究现状指出今后波浪能发电装置的发展趋势及前景。     

美国波浪能发电场建设对中国波浪能的启示

美国海域波浪资源丰富,在波浪能开发及利用方面开展了许多卓有成效的工作,值得借鉴和参考.通过分析美国地理环境特点、气候环境特点、波浪能资源分布特点,获得了美国波浪能资源概况;通过分析美国能源使用情况、波浪能资源开发现状及规划,掌握了美国波浪能的开发政策及方向;通过归纳波浪能发电场建设的关键因素、现状,阐述了建设波浪能发电...     

双浮体—棘轮式波浪能发电装置

简述了一种新型的波浪能发电装置,其特点是利用两个浮体因波浪的波动而产生相对倾斜来收集波浪能,采用两个反向棘轮和一对链轮组,将往复运动转换成旋转运动,再带动发电机发出电力,是一种结构简单,造价低廉,容易实施的波浪能发电装置。     

波浪能发电技术研究

海洋波浪能是一种清洁环保并且可再生的新型能源.通过介绍波浪能发电装置设计原理,对各种装置的工作原理进行了分析,并总结了其优缺点及应用场合,最后探讨了波浪能发电存在的问题和发展前景.     

波浪能发电

波浪能源转换成电能的过程,主要是由波浪的能源转换成力学能（一次转换）,之后再将力学能提供发电机发电（二次转换）,进而获得电力。     

海洋波浪能发电技术的发展与应用

随着世界能源的日趋紧张和环境问题的日益凸显,海洋波浪能作为一种清洁、可再生能源而备受世界各国的重视。文章首先介绍了波浪能的定义、成因与优点,针对海洋波浪能发电技术的基本原理、能量转换系统等作了全面综述,介绍了国内外海洋波浪能发电技术的进展和主要波能装置。     

Development of an electrical power take off system for a sea-test scaled offshore wave energy device

This paper details the design, deployment and operation of a power take off system for a 1:4 scale offshore Oscillating Water Column (OWC) Wave Energy Converter (WEC). Ocean energy device prototypes at this scale present a unique set of challenges in that the integration of prime movers and generators typically begins to take place at this particular development stage, which may also represent first deployment at sea.The presence of electrical equipment and rotating machinery in the offshore environment brings its own engineering and operational difficulties. Moreover, such devices are typically not grid connected, necessitating the development of custom power conversion and control equipment. The paper describes the design considerations, details of design, deployment experiences, operational experiences of such a system and concludes with recommendations for future projects in the area.     

Speed control of oil-hydraulic power take-off system for oscillating body type wave energy converters

The variable displacement oil-hydraulic pumps for the Power Take-Off (PTO) of wave energy converters must work above 80% of maximum displacement in order to have an overall efficiency of approximately 94.5%. This is achieved by controlling their rotational speed when the oil-hydraulic power fluctuates in time. Three speed control strategies have been presented, the first fixing the maximum possible speed in each sea state, the second by slowly varying the pump speed between speed peak values and average ones, and the third by working with highly variable speed reference values. The worst pump efficiency is achieved with the first strategy while the best one with the third strategy. However, the first has less impact than the third one in the pump lifecycle. On the other hand, the second strategy is used to make a trade-off between pump efficiency and lifecycle. However, this paper presents a fourth speed control strategy, which is a hybrid of the second and third strategies. So, the objectives of this paper were to know if these strategies are implementable in a test rig and also on a new PTO concept and determining what modifications should be introduced in these PTO strategies and hardware. This paper also contributes with the application of new methodologies in this field of research for the modelling of pump efficiency and pressure control, such as Neuro-Fuzzy modelling and Fuzzy Logic control systems.     

Shape optimisation of floating wave energy converters for a specified wave energy spectrum

Ocean wave energy is one of the world's most powerful forms of energy and the energy density in ocean waves is the highest among renewable energy sources. Wave energy converters are employed to harness this energy and convert it into usable electrical energy. However, in order to efficiently extract the energy, the wave energy converter must be optimised in the design stage. Therefore, in this paper, a methodology is presented which aims to optimise the structural geometric configuration of the device to maximise the average power extraction from its intended deployment site. Furthermore, a case study of the Atlantic marine energy test site, off the west coast of Ireland, is undertaken in order to demonstrate the methodology. Using the average annual wave energy spectrum at this site as the input, the optimum structural geometric configuration was established, along with an analysis of the optimum configuration for different radius devices. In addition, the optimum damping coefficient of the PTO mechanism is determined and the total mean absorbed power for the structure at the site over the entire scatter diagram of data is calculated.     

Tidal effect compensation system for point absorbing wave energy converters

Recent studies show that there is a correlation between water level and energy absorption values for the studied wave energy converters: the absorption decreases when the water levels deviate from average. The situation appears during tides when the water level changes significantly. The main objective of the paper is to present a first attempt to increase the energy absorption during tides by designing and realizing a small-scale model of a point absorber equipped with a device that is able to adjust the length of the rope connected to the generator. The adjustment is achieved by a screw that moves upwards in the presence of low tides and downwards in the presence of high tides. Numerical results as well as experimental tests suggest that the solution adopted to minimize the tidal effect on the power generation shows potential for further development.     

Study of a longitudinal flux permanent magnet linear generator for wave energy converters

A directly coupled linear permanent magnet generator of longitudinal flux‐type is investigated. The generator will be used for power take‐off in a wave energy converter. A combined field‐ and circuit model, solved by a time stepping finite element technique, is used to model and analyse the electromagnetic behaviour of the machine. A large number of simulations form the basis of a design study where the influence of armature current level, number of cables per slot, and pole width is investigated with respect to efficiency, generator size, and the load angle. A case study is performed for a chosen generator design. The electromagnetic behaviour is examined both for nominal load and for overloads. The generator has a nominal output power of 10 kW for a constant piston speed of 0.7 ms^?1. The electromagnetic efficiency at nominal load is 86.0%, the load angle 6.6°, and the power fluctuation 1.3%. At 300% overload the load angle barely exceeds 12° and the cable temperature is below 25°C provided that the stator back is thermally connected to the sea water. The numerical calculations have been verified for small speeds by experiments. Copyright © 2006 John Wiley & Sons, Ltd.     

Increases in the average power output of wave energy converters using quiescent period predictive control

The potential of controlling wave energy converters, (WEC), by deterministic prediction of large damaging waves is introduced and shown to offer very substantial increases in the annual average power output of such devices. Results obtained for idealised WEC models show that the potential exists for this increase to be at least a factor of two. Numerical simulations of actual dynamical models for both point absorbers and directionally sensitive devices employing practical control strategies show that most of this potential can actually be realised. The control of large scale wave farms using quiescent period predictive control is likely to be most cost effective using master/slave WEC systems. To achieve the computational savings that will allow this strategy analytic approximations are required for the response of WECs with time varying coefficients, preliminary forms of these have also been introduced.     

波浪能独立稳定电站负载抗冲击性研究

采用蓄能稳压方式把不稳定能量的输入转换为稳定能量的输出是保证可再生能源发电质量和提高能量转换效率的一种有效方法,波力电站采用该方法实现了独立稳定发电.波浪能的波动性及蓄能稳压系统的特点导致了波力电站发电的间歇性和开始发电时电压的冲击性,这些特点决定了负载配置的特殊性.文章论述了具有抗冲击性负载系统的设计思想、实现方法和试验结果.实际海况试验结果表明,该系统有效地避开了发电机的尖峰电压,不仅实现了对白炽灯的正常供电,还实现了对蓄电池的正常充电.     

Testing and control of a power take-off system for an oscillating-water-column wave energy converter

The paper concerns the development of the PTO (power take-off) control of an OWC (oscillating-water-column) spar-buoy wave energy converter. The OWC spar-buoy is an axisymmetric device consisting of a submerged vertical tail tube open at both ends, rigidly fixed to a floater that moves essentially in heave. The oscillating motion of the internal free surface relative to the floater-tube set, produced by the incident waves, makes the air flow through a novel self-rectifying air turbine: the biradial turbine. To reduce the losses of the PTO system at partial load, an electrical generator with a rated power twice the maximum expected average power conversion of the buoy was adopted. The control of the turbine-generator set under highly energetic sea-state conditions was experimentally investigated by means of tests performed in a PTO test rig. In the reported tests, the hydrodynamics of the OWC spar-buoy and the aerodynamics of the air turbine were numerically simulated in real-time and coupled with the experimental model of the turbine/electrical generator set in a hardware-in-the-loop configuration. The experimental results allowed the dynamic behaviour of the PTO to be characterized and provided validation of the proposed control algorithms that ensure operation within safe limits.