Novel hydraulic mechanism-based output power regulation for the wave energy converter

2021 ◽  
Vol 110 ◽  
pp. 102587
Author(s):  
Dazhou Geng ◽  
Yang Zheng ◽  
Qijuan Chen ◽  
Xuhui Yue ◽  
Donglin Yan
Author(s):  
Seyed Milad Mousavi ◽  
Majid Ghasemi ◽  
Mahsa Dehghan Manshadi ◽  
Amir Mosavi

Accurate forecasts of ocean waves energy can not only reduce costs for investment but it is also essential for management and operation of electrical power. This paper presents an innovative approach based on the Long Short Term Memory (LSTM) to predict the power generation of an economical wave energy converter named “Searaser”. The data for analyzing is provided by collecting the experimental data from another study and the exerted data from numerical simulation of searaser. The simulation is done with Flow-3D software which has high capability in analyzing the fluid solid interactions. The lack of relation between wind speed and output power in previous studies needs to be investigated in this field. Therefore, in this study the wind speed and output power are related with a LSTM method. Moreover, it can be inferred that the LSTM Network is able to predict power in terms of height more accurately and faster than the numerical solution in a field of predicting. The network output figures show a great agreement and the root mean square is 0.49 in the mean value related to the accuracy of LSTM method. Furthermore, the mathematical relation between the generated power and wave height was introduced by curve fitting of the power function to the result of LSTM method.


2017 ◽  
Vol 863 ◽  
pp. 175-182
Author(s):  
Yi Ming Zhu ◽  
Zi Rong Luo ◽  
Zhong Yue Lu ◽  
Jian Zhong Shang

This paper proposed a novel micro wave energy converter which can convert irregular wave energy into rotating mechanical energy, then into electrical energy. The device consists of an energy absorption part and an energy conversion part. In details, the blades are installed on the absorber circumferentially and averagely, which are capable of converting the vertical motion of the surface body to continuous rotation of the absorber and leading to a great increase in efficiency. A physical prototype was built to test the performance of the novel generator and optimize the design parameters. In the experiment part, a linear motion electric cylinder was used as the drive power to provide the heaving motion for the device. And the experiment platform was built for modeling a marine environment. Also, a data acquisition program was edited in Labview. Thus, the experiment analyzed the influence of amplitude, frequency, blade angle and resistance value to the output power, and then obtained the optimum parameters combination which can maximize the value of the output power. The result will provide reference for the device’s further application.


2018 ◽  
Vol 161 ◽  
pp. 337-349 ◽  
Author(s):  
Hoang-Thinh Do ◽  
Tri-Dung Dang ◽  
Kyoung Kwan Ahn

2019 ◽  
Vol 7 (7) ◽  
pp. 223 ◽  
Author(s):  
Sun ◽  
Shang ◽  
Luo ◽  
Lu ◽  
Wu ◽  
...  

Unmanned marine equipment has been increasingly developed for open seas. The lack of efficient and reliable power supply is currently one of the bottlenecks restricting the practical application of these devices. In order to provide a viable power supply method for unmanned marine equipment, such as sonic buoys and sea robots, we originally propose a novel small-scale flexible blade wave energy converter (WEC) based on self-adaptable counter-rotating operation mechanism. The flexible blade WEC is designed on the basis of the rigid blade WEC with the caging device. This paper identifies the key factors affecting WEC performance through theoretical analysis. According to the numerical simulation analysis, the output mechanical power of the double-layer absorber is 12.8 W, and the hydraulic efficiency is 36.3%. The results of the verification experiment show that the peak power of WEC is 5.8 W and the average power is 3.2 W. The WEC with 65Mn flexible blade under most experimental conditions has the best performance when the blade thickness is 0.10 mm. The study shows that the new generation WEC can effectively overcome the excessive fluctuation of the output power of the previous generation WEC. The output power curve of the novel WEC is relatively smooth, which is conducive to its smooth operation and subsequent utilization and storage of electrical energy.


2016 ◽  
Vol 78 (5-7) ◽  
Author(s):  
Masjono Masjono ◽  
Salama Manjang ◽  
Dadang A. Suriamiharja ◽  
M. Arsyad Thaha

The prediction of converted energy by one way gears wave energy converter may be influenced by non-linearity properties of the ocean waves. To date there has not been an adequate analytical model to predict the power production of one way gear wave energy converter under irregular wave condition. In this work, analytical model is developed to describe the interaction of one way gear wave energy converter that utilized gravity force of the gravityweight (M) with irregular ocean waves using JONSWAP (Joint North Sea Wave Project) model. This interaction model has been simulated numerically by means of computer software. The simulation result showed that wave height is strongly determining the converted output power. The outcome of harnessing the gravity force instead of buoyant force of this proposed model that commonly used by the previous wave energy converter demonstrate significant potential output power. The proposed model can be used to design feasible and efficient wave energy converter.


Author(s):  
Xiaofan Li ◽  
Chien-An Chen ◽  
Qiuchi Xiong ◽  
Robert Parker ◽  
Lei Zuo

In this paper, a two-body self-react wave energy converter with a novel mechanical Power Take-off (PTO) is introduced. The PTO rectifies the mechanical motion and regulates the flow with a mechanism called Mechanical Motion Rectifier (MMR), which converts the reciprocating motion of the ocean wave into unidirectional rotation of the generator. The overall system is analyzed in both time and frequency domain. In time domain, the piecewise non-linear dynamic model of the MMR PTO is derived, and parameters that could significantly influence the MMR property is extracted. By building the model into WEC-Sim, a time domain wave energy converter (WEC) simulation tool, to simulate and evaluate the performance of the PTO. In addition, the system is modelled as a two-body vibration system for frequency domain analysis in order to further investigate and optimize the proposed wave energy converter. The tunable parameters within the system, including the equivalent mass, the equivalent damping coefficient, and the PTO stiffness, are discussed based on the criteria of maximization of the total output power. To verify the theoretical analysis, a bench test prototype is developed and tested on a hydraulic test machine. The experimental results in line with the derived model and can be used for reasonable estimation on the output power of the proposed system in real ocean conditions.


Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3567
Author(s):  
Hong Li ◽  
Bo Zhang ◽  
Li Qiu ◽  
Shiyu Chen ◽  
Jianping Yuan ◽  
...  

This paper presents a coordinated control based on the advection consensus control algorithm to implement power dispatch for each wave-energy converter (WEC) in a WEC array. Under unbalanced conditions, the proposed algorithm is applied in order to control each WEC to output power coordinately, to enable the total output power of the WEC array to satisfy the time-varying load requirements. The purpose of the additional energy storage unit on each WEC is to smooth the power output of each WEC and to obtain more margin. Case studies include the demonstration of some simulations and experiments, and the results show that the WEC array under the proposed control method can accurately respond to the demand for power supply under unbalanced initial conditions.


Author(s):  
Xiaofan Li ◽  
Changwei Liang ◽  
Lei Zuo

The design and dynamic analysis of a two-body wave energy converter with 50W average output power is presented in this paper. The wave energy is extracted through the relative motion between a floating buoy and a submerged body, both oscillating in the heave direction. A ball screw system is used to convert the linear relative motion into bidirectional rotation of the screw. Moreover, a mechanical motion rectifier (MMR) is used in the power take-off (PTO) design and convert the bidirectional rotation into unidirectional rotation of generator by using two one-way bearings in the gear system. The dynamic equation of this two-body wave energy converter is established by considering the engagement and disengagement of the one-way bearings in the PTO system. The simulation results in the regular and irregular waves are presented and the average output power of the proposed wave energy converter under different wave condition are estimated.


Author(s):  
Wei Peng ◽  
Junwei Ma

Abstract Wave energy is favored by more and more people because of its wide distribution, pollution-free, renewable and many other advantages. Among numerous wave energy converting devices, the converters using floating breakwaters are recognized to be quite promising as the construction and maintenance cost can be shared. In this study, a shoreline wave energy converter (WEC) is proposed which consists of a floating breakwater arranged along the wave direction and restricted to only have vertical degree of motion. Making use of the motion of breakwaters, a dynamo is able to convert the wave power to electricity. At the same time, the incoming waves can be attenuated due to the complex interaction between waves and the floating structure. A scale model was built in the laboratory at Hohai University, and then employed to investigate the performance of developed wave energy device. In the physical model, dynamos and resistance were employed as the power take-off (PTO) system, and the instantaneous output power could be calculated using the measured data. Experimental results show that the resonance state of float plays an important role for the wave energy extraction, and the hydrodynamic efficiency of the device under the resonance state can be up to 41.8% for single breakwater, counting in the internal energy converted by the dissipative force. When subjected to shorter waves, the PTO damping encourages the wave reflection; whereas, more wave energy is dissipated or transformed to power for longer waves. Meanwhile, the PTO damping is also a negative factor for the wave overtopping reduction as the motion of float may be restrained considerably. Last but not the least, the PTO load is proved to be a significant parameter for the optimization the output power, and a strategy must be found to achieve the best power conversion under the dominant wave conditions.


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