Wave power

About: Wave power is a research topic. Over the lifetime, 2671 publications have been published within this topic receiving 41439 citations. The topic is also known as: wind wave energy & sea wave energy.

Wave Energy in Korean Seas from 12-Year Wave Hindcasting

Abstract: In this study, a numerical simulation is performed to produce wave hindcasting data from 2007 to 2018 for the assessment of wave energy resources in the sea waters of Korea. The hindcasting data are obtained with a relatively fine spatial resolution of 1/20° covering 120–150 °E longitude and 22.4–47.6 °N latitude using the Simulating WAves Nearshore wave model (SWAN). Three different wind fields, those of the European Centre for Medium-Range Weather (ECMWF), National Centers for Environmental Prediction (NCEP), and Japan Meteorological Agency (JMA), are used for the numerical wave simulation. It is observed that the wind field dataset of JMA exhibits the best agreement with available field observation data. For this reason, the wave energy resources are evaluated based on the data hindcasted using the JMA wind field. It is found that the overall magnitudes of wave energy are larger in winter than in summer. The wave energy in August, however, is comparable to the mean wave energy during winter because of the influence of frequent high wave events caused by typhoons. The highest monthly average wave power around Yellow Sea, South Sea, East Sea, and Jeju Island are 13.3, 18.2, 13.7, and 40 kW/m, respectively.

Oscillating water column type wave power generating device based on piezoelectric effect

Abstract: The invention discloses an oscillating water column type wave power generating device based on the piezoelectric effect. The device comprises an automatic direction-adjustment wave energy collecting mechanism, an air pressure energy storage mechanism, an air-driving piezoelectric generating mechanism and a multi-freedom-degree brush mechanism used for transmitting electric energy of the air-driving piezoelectric generating mechanism; the automatic direction-adjustment wave energy collecting mechanism comprises an oscillating water column type wave power collector, a direction-adjustment empennage and a location portion used for installing and locating the oscillating water column type wave power collector; the air pressure energy storage mechanism comprises a pressure energy storage device, and an oscillating water column air chamber is communicated with the pressure energy storage device through an air inlet pipe; the air-driving piezoelectric generating mechanism comprises piezoelectric patches and a compression driving portion used for compressing the piezoelectric patches. By means of the oscillating water column type wave power generating device, sustainable and durable electric energy can be provided, and the wireless energy supply problem of small and medium size electric appliance in the sea is solved.

Adaptive Sliding Mode Control for a Double Fed Induction Generator Used in an Oscillating Water Column System

Abstract: Wave power conversion systems are nonlinear dynamical systems that must endure strong uncertainties. Efficiency is a key issue for these systems, and the application of robust control algorithms can improve it considerably. Wave power generation plants are typically built using variable speed generators, such as the doubly fed induction generator (DFIG). These generators, compared with fixed speed generators, are very versatile since the turbine speed may be adjusted to improve the efficiency of the whole system. Nevertheless, a suitable speed controller is required for these systems, which must be able to avoid the stalling phenomenon and track the optimal reference for the turbine. This paper proposes a sliding mode control scheme aimed at oscillating water column (OWC) generation plants using Wells turbines and DFIGs. The contributions of the paper are (1) an adaptive sliding mode control scheme that does not require calculating the bounds of the system uncertainties, (2) a Lyapunov analysis of stability for the control algorithm against system uncertainties and disturbances, and (3) a validation of the proposed control scheme through several simulation examples with the Matlab/Simulink suite. The performance results, obtained by means of simulations, for a wave power generation plant (1) evidence that this control scheme improves the power generation of the system and (2) prove that this control scheme is robust in the presence of disturbances.

Hydraulic transmission system of power decoupling type wave power generating device and control method of hydraulic transmission system

Abstract: The invention discloses a hydraulic transmission system of a power decoupling type wave power generating device and a control method of the hydraulic transmission system of the power decoupling type wave power generating device. The transmission system is composed of an energy capturing unit, a pressure protection unit, a rectification unit, a voltage transformation unit, a speed regulating unit, an energy storage unit and a power generating unit. According to the hydraulic voltage transformation principle and the transmission system of the device, shaft connection is conducted on a hydraulic motor and a variable pump, low-voltage and large-flow input power is converted into high-voltage and small-flow output power, and therefore output power is more suitable for transmission and control; meanwhile, according to the control method, the voltage transformation ratio is adjusted in real time according to different operation sea conditions to stabilize the output rotation speed of the hydraulic motor and the output rotation speed of an electric generator, a high-voltage bag type accumulator is used for further stabilizing voltage fluctuation, conversion from a voltage transformation network to a quasi-constant-voltage network is achieved, and power coupling of input and output of the transmission system of the wave power generating device is achieved.